CHEMICAL AND BIOLOGICAL SCIENCES

Marek Pruski Senior Scientist and Adjunct Professor of Chemistry, Iowa State University 230 Spedding Hall Ames Laboratory Iowa State University Ames, IA 50011 Phone 515-294-2017 FAX 515-294-5233 marek@ameslab.gov

PERSONAL HISTORY

• B.S. 1977, Nicholas Copernicus University, Torun, Poland
• Ph.D. 1981, Nicholas Copernicus University, Torun, Poland
• 1982-1985, Lecturer and Research Assistant, Nicholas Copernicus University, Torun, Poland
• 1985-1988, Postdoctoral Fellow, Ames Laboratory, Iowa State University
• 1988-present, Associate Scientist, Scientist and Senior Scientist, Ames Laboratory
• 1998, 2000, Visiting Professor, University of Lille, France
• 2003, Visiting Professor, University of Caen, France

RESEARCH INTERESTS

Our group develops and applies transient techniques in solid-state nuclear magnetic resonance (NMR) to probe the chemical and physical properties of materials involved in heterogeneous catalysis, surface science and materials science. The work on catalysts, which in recent years constituted most of the research effort, focuses on studying the properties of surfaces, as well as the molecular structure, dynamics and reactions of the adsorbed species. Development of new solid-state NMR methods for these studies is the second major research area. Current efforts include the development of techniques based on multiple-quantum magic angle spinning (MQMAS) NMR, homo- and hetero-nuclear correlation experiments for spin-1/2 and quadrupolar nuclei, methods utilizing ultrafast MAS and methods for measuring internuclear distances in solids.

1. High-resolution solid-state NMR methods

1.1. Half-integer quadrupolar nuclei. In the past several years, our group has developed and exploited high-resolution methods for studying half-integer quadrupolar spins (70% of all NMR-active nuclei).  Quadrupolar broadening contains higher order orientational terms of significant magnitude and isotropic resolution can only be achieved by applying complex motions of the sample (double rotation, dynamic angle spinning) or by combining magic angle spinning and multiple-quantum NMR in an MQMAS experiment. Several new techniques have been developed from this effort, including CP-MQMAS (MQMAS with Cross Polarization), MQ-REDOR (MQ Rotational Echo Double Resonance) and MQ-HETCOR (MQ HETeronuclear CORrelation spectroscopy). These techniques extended the capabilities of NMR to probing the intermediate range order (0.5-1 nm) in inorganic solids under high-resolution conditions.

Applications of these methods included measurements of through-space and through-bond interatomic connectivities and distances between spin-1/2 (e.g. ¹H, ¹⁹F, ²⁹Si and ³¹P) and quadrupolar (e.g. ¹¹B, ²³Na and ²⁷Al) nuclei in several types of molecular sieves, glasses and other materials. Examples of MQ-HETCOR spectra revealing through-bond (via refocused INEPT) and through-space (via dipolar cross polarization) connectivities are shown in Figures 1a and 1b, respectively. We also conducted experimental and theoretical studies directed toward better understanding of the spin dynamics involved in MQMAS-based experiments on quadrupolar nuclei.

1.2. Ultrafast MAS. Our recent interests include exploitation of state-of-the-art fast MAS in homo- and heteronuclear NMR experiments involving pairs of spin-1/2 nuclei (e.g. ¹H-¹H, ¹H-¹³C, ¹H-²⁹Si). This approach proved useful in the studies of functionalized silica surfaces, where MAS at rates ≥ 40 kHz can provide adequate ¹H-¹H decoupling. Additional advantages of using fast MAS in HETCOR NMR include easy setup, lack of scaling factors, and ease of acquisition of sideband-free spectra. The loss of sensitivity due to small rotor volume (less than 10 mL), is offset by low requirements for the RF magnetic field homogeneity within the sample.

Utilizing fast MAS, highly resolved ¹H-¹³C HETCOR NMR spectra of various organic groups covalently bound to the silica surface were obtained without ¹³C enrichment (see Figure 2a). In addition, the sensitivity of ¹H-²⁹Si HETCOR NMR was significantly increased by applying a CPMG train of refocusing p pulses to the ²⁹Si spins. The experiments performed thus far in our laboratory indicated that sensitivity gains exceeding one order of magnitude, or two orders of magnitude in the total acquisition time, are common on the silica surfaces. These experiments require unusually long acquisition periods for each free induction decay, which can exceed the duration of the delay between consecutive scans. Under such circumstances, fast MAS offers an additional advantage in that it can be used with low power heteronuclear decoupling. The acquisition of ¹H-²⁹Si HETCOR spectrum shown in Figure 2b would not be possible without using the CPMG refocusing. The sensitivity gain can be also exploited in ²⁹Si-²⁹Si double-quantum (DQ) (Figure 2c) and in ²⁷Al-²⁹Si correlation spectroscopy of catalytic materials, especially aluminosilicates and zeolites.

1.3. Other methods. We also explore new methods for studying mesoporous mixed oxides. These oxides often include spin-1/2 (e.g. ^111/113Cd, ¹¹⁷Sn) or half-integer quadrupolar (e.g. ¹⁷O, ²⁵Mg, ⁴³Ca, ^47/49Ti, ⁷⁸Sr and ⁹⁵Mo) nuclei, which are difficult to observe because of low magnetogyric ratio and/or low natural abundance. However, acquisition of solid-state NMR spectra of these ‘challenging’ nuclei is becoming possible, if not routine, using more sophisticated instrumentation (high-field magnets and more sensitive probes), isotope enrichment, and improved protocols for excitation/detection.

Since some of the systems and reactions of interest to us involve liquid-solid interfaces, we are also interested in the use of NMR for studying structures and molecular dynamics in suspensions, where tethered and reacting species exhibit a wide spectrum of mobilities. In the long run, these studies will allow correlating the mobility of surface species with catalytic activity.

2. Studies of heterogeneous catalysts and other complex materials by solid-state NMR

2.1. The use and development of new techniques in solid-state NMR is a vital part of the catalysis program at Ames Laboratory. The main area of current interest involves characterization of functionalized silica- and/or alumina-based, single-site mesoporous catalysts with controlled, nanostructured surface and particle morphology. One- and two-dimensional (1D and 2D) ¹H, ²⁹Si and ¹³C NMR methods are being used to (1) detail the structures of non-functionalized MCM-41 mesoporous silica nanoparticles, (2) study the structures and absolute/relative concentrations of various moieties inside the mesopores, (3) determine their spatial distribution, orientation with respect to the surface and dynamic behavior, and (4) monitor template removal and the catalysts’ stability under reaction conditions. Several classes of bifunctional materials are thoroughly characterized, including catalysts for hydrogenation, polymerization and oxidation reactions, in which reaction selectivity is controlled using the novel concept of gatekeepers. Recent developments in solid-state NMR will be further exploited to characterize the mesoporous scaffolds composed of other metal oxides, including Cr₂O₃, MnO, ZnO, CdO and CaO.

2.2. We also work on (i) characterization of combined homogeneous-heterogeneous, silica-based tethered catalysts for enantioselective hydrogenation and oxidation reactions, by using a suite of 1D and 2D measurements involving ¹H, ¹¹B, ¹³C, ¹⁹F, ²⁹Si and ³¹P nuclei; (ii) ²⁷Al, ⁷Li, ²³Na and H NMR studies of novel materials for hydrogen storage - non-transition metal-based complex hydrides, where the metal, metalloid or nonmetal atom is coordinated by two to six hydrogen atoms, and which are synthesized by means of a solvent-free technique (mechanochemistry) or by chemical approaches (self-assembled micelles); and (iii) studies of industrial catalysts.

RECENT PUBLICATIONS

J.-P. Amoureux, J. Trebosc, J. Wiench and M. Pruski, "HMQC and Refocused-INEPT Experiments Involving Half-Integer Quadrupolar Nuclei in Solids", J. Magn. Reson., accepted.

R. Kumar, H.-T. Chen, J.L.V. Escoto, V.S.-Y. Lin and M. Pruski, "Template Removal and Thermal Stability of Organically Functionalized Mesoporous Silica Nanoparticles", Chem. Mat., 18, 4319-4327 (2006).

S.M. Cabral de Menezes, Y.L. Lam, K. Damodaran and M. Pruski, "Modification of H-ZSM-5 Zeolites with Phosphorus. 1. Identification of Aluminum Species by ²⁷Al Solid-State NMR and Characterization of their Catalytic Properties", Micropor. Mesopor. Mater., 95, 286-295 (2006).

K. Damodaran, J.W. Wiench, S.M. Cabral de Menezes, Y.L. Lam, J. Trebosc, J.-P. Amoureux and M. Pruski, "Modification of H-ZSM-5 Zeolites with Phosphorus. 2. Interaction between Phosphorus and Aluminum Studied by Solid-State NMR Spectroscopy", Micropor. Mesopor. Mater., 95, 296-305 (2006).

K.J. Stanger, J.W. Wiench, M. Pruski, J.H. Espenson, G.A. Kraus and R.J. Angelici, "Catalytic Oxidation of a Thioether and Dibenzothiophenes Using Oxorhenium(V) Dithiolate Complex Tethered on Silica", J. Mol. Catal. A, 243, 158-169 (2006).

J.W. Wiench, G. Tricot, L. Delevoye, J. Trebosc, J. Frye, L. Montagne, J.-P. Amoureux, M. Pruski, "SPAM-MQ-HETCOR: an Improved Method for Heteronuclear Correlation Spectroscopy between Quadrupolar and Spin-1/2 Nuclei in Solid-State NMR", Phys. Chem. Chem. Phys., 8, 144-150 (2006).

C. Li, M. Akinc, J. W. Wiench, M. Pruski and C. H. Schilling, "Relationship between Water Mobility and Viscosity of Nanometric Alumina Suspensions", J. Am. Ceram. Soc., 88, 2762-2768 (2005).

H.-T. Chen, S. Huh, J.W. Wiench, M. Pruski and V.S.-Y. Lin, "Dialkylaminopyridine-Functionalized Mesoporous Silica Nanosphere as an Efficient and Highly Stable Heterogeneous Nucleophilic Catalyst", J. Am. Chem. Soc., 127, 13305-13311 (2005).

J. Trebosc, J.W. Wiench, S. Huh, V.S-Y. Lin and M. Pruski, "Studies of Organically Functionalized Mesoporous Silicas Using Heteronuclear Solid-State Correlation NMR Spectroscopy under Fast Magic Angle Spinning", J. Am. Chem. Soc., 127, 7587-93 (2005).

J. Trebosc, J.W. Wiench, S. Huh, V.S-Y. Lin and M. Pruski, "Solid-State NMR Study of MCM-41-type Mesoporous Silica Nanoparticles", J. Am. Chem. Soc., 127, 3057-3068 (2005).

S. Huh, H.-T. Chen, J.W. Wiench, M. Pruski and V.S.-Y. Lin, "Cooperative Catalysis by General Acid and Base Bifunctionalized Mesoporous Silica Nanospheres", Angew. Chem., 44, 1826-30 (2005).

J.-P. Amoureux, J. Trebosc, J.W. Wiench, D. Massiot and M. Pruski, "Measurement of J-Couplings between Spin-1/2 and Quadrupolar Nuclei by Frequency Selective Solid-State NMR", Solid State NMR, 27, 228-232 (2005).

J.W. Wiench, C.J. Fontenot, J. Woodworth, G.L. Schrader, M. Pruski and S.C. Larsen, "Magnetic Resonance Investigation of Vanadia and Vanadium-Molybdenum Gels Synthesized with Peroxovanadate Precursors", J. Phys. Chem. B.,109, 1756-1762 (2005).

J. Trebosc, J.-P. Amoureux, L. Delevoye, J.W. Wiench and M. Pruski, "Frequency-Selective Measurement of Heteronuclear Scalar Couplings in Solid-State NMR", Solid State Sci. 6, 1089-1095 (2004).

J.W. Wiench and M. Pruski, "Probing Through Bond Connectivities with MQMAS NMR", Solid State NMR, 26, 51-55 (2004).

J.W. Wiench, V.P. Balema, V.K. Pecharsky and M. Pruski, "Solid State ²⁷Al NMR Investigation of Thermal Decomposition of LiAlH₄", J. Solid State Chem., 177, 648-653 (2004).

D.R. Radu, C.-Y. Lai, J.W. Wiench, M. Pruski and V.S.-Y. Lin, "Gatekeeping Layer Effect: A Poly(lactic acid)-Coated Mesoporous Silica Nanosphere-Based Fluorescence Probe for Detection of Amino-Containing Neurotransmitters", J. Am. Chem. Soc., 126, 1640-1641 (2004).

S. Huh, H.-T. Chen, J.W. Wiench, M. Pruski and V.S.-Y. Lin, "Controlling the Selectivity of Competitive Nitroaldol Condensation by Using a Bifunctionalized Mesoporous silica Nanosphere-Based Catalytic System", J. Am. Chem. Soc., 126, 1011-1012 (2004).

S. Huh, J.W. Wiench, J.-C. Yoo, M. Pruski and V.S.-Y. Lin, "Organic Functionalization and Morphology Control of Mesoporous Silicas via a Co-condensation Synthesis Method", Chem. Mater., 15, 4247-4256 (2003).

S. Huh, J.W. Wiench, B.G. Trewyn, S. Song, M. Pruski and V.S.-Y. Lin, "Tuning of Particle Morphology and Pore Properties in Mesoporous Silicas with Multiple Organic Functional Groups", Chem. Comm., 2364-2365 (2003).

J. Trebosc, J.-P. Amoureux, J.W. Wiench and M. Pruski, "Simultaneous Frequency-Selective Solid-State NMR Analysis of Internuclear Distances and Through-Bond Connectivities in the Presence of Quadrupolar Nuclei", Chem. Phys. Lett., 374, 432-438 (2003).

K.J. Stanger, J.W. Wiench, M. Pruski and R.J. Angelici, "³¹P NMR and IR Characterization of Enantioselective Olefin and Arene Hydrogenation Catalysts Containing a Rhodium-Chiral Phosphine Complex Tethered on Silica", J. Mol. Catal. A, 195, 63-82 (2003).

V.P. Balema, J.W. Wiench, M. Pruski and V.K. Pecharsky, "Solvent-free Mechanochemical Synthesis of Two Pt Complexes: Cis-(Ph₃P)₂PtCl₂ and Cis-(Ph₃P)₂PtCO₃", Chem. Commun., 1606-1607 (2002).

C.J. Fontenot, J.W. Wiench, G.L. Schrader and M. Pruski, "¹⁷O MAS and 3QMAS NMR Investigation of Crystalline V₂O₅ and Layered V₂O₅^.nH₂O Gels", J. Am. Chem. Soc., 124, 8435-8444 (2002).

V.P. Balema, J.W. Wiench, M. Pruski, and V.K. Pecharsky, "Mechanically Induced Solid-State Generation of Phosphorus Ylides and the Solvent-Free Wittig Reaction", J. Am. Chem. Soc., 124, 6244-6245 (2002).

V.S.-Y. Lin, D. Radu, M.-K. Han, W. Deng, S. Kuroki, B.H. Shanks and M. Pruski, "Oxidative Polymerization of 1,4-Diethynylbenzene into Highly Conjugated Oligo(phenylene butadiynylene) within the Channels of Surface-Functionalized Mesoporous Silica and Alumina Materials", J. Am. Chem. Soc., 124, 9040-9041 (2002).

M. Pruski, J.-P. Amoureux and C. Fernandez, "Progress in High Resolution Solid State NMR of Quadrupolar Nuclei: Applications to Porous Materials and Catalysts", NATO Series, Mathematics, Physics and Chemistry, 76, 107-114 (2002).

J.-P. Amoureux and M. Pruski, "Advances in MQMAS NMR", Encyclopedia of Nuclear Magnetic Resonance, Ed. D. M. Grant and R. K. Harris, Volume 9: Advances in NMR, 226-251, John Wiley & Sons Ltd., Chichester, (2002).

W. Deng, P. Bodart, M. Pruski and B.H. Shanks, "Characterization of Mesoporous Alumina Molecular Sieves Synthesized by Nonionic Templating", Micropor. Mesopor. Mater., 52, 169-177 (2002).

N. Savargaonkar, D.O. Uner, M. Pruski and T.S. King, "Determination of Hydrogen Adsorption and Desorption Kinetics on Silica Supported Pt, Rh and Ru Catalysts Studied by Solid State ¹H NMR", Langmuir, 18, 4005-4009 (2002).

J.-P. Amoureux and M. Pruski, "Theoretical and Experimental Assessment of Single- and Multiple-Quantum Cross Polarization in Solid-State NMR", Mol. Phys., 100, 1595-1613 (2002).

V.P. Balema, J.W. Wiench, M. Pruski and V.K. Pecharsky, "Solvent-free Mechanochemical Synthesis of Phosphonium Salts", Chem. Commun., 724-725 (2002).

C. Fernandez, C. Morais, J. Rocha and M. Pruski, "High-resolution Heteronuclear Correlation Spectra between ³¹Pand ²⁷Al in Microporous Aluminophosphates", Solid State NMR, 21, 61-70 (2002).

R. Lefort, J.W. Wiench, M. Pruski and J.-P. Amoureux, "Optimization of Data Acquisition and Processing in Carr-Purcell-Meiboom-Gill Multiple Quantum Magic Angle Spinning Nuclear Magnetic Resonance", J. Chem. Phys., 116, 2493-2501 (2002).

J.W. Wiench, B. Tischendorf, J.U. Otaigbe and M. Pruski, "Structure of Zinc Polyphosphate Glasses Studied by Two-Dimensional Solid and Liquid State NMR", J. Mol. Struct., 602-603, 145-158 (2002).

V.P. Balema, J.W. Wiench, K.W. Dennis, M. Pruski and V.K. Pecharsky, "Titanium Catalyzed Solid-State Transformations in LiAlH₄ During High-Energy Ball-Milling", J. Alloys Compds., 329, 108-114 (2001).

C. Fernandez and M. Pruski, "Measurement of MQMAS Heteronuclear Correlation Spectra in Microporous Aluminophosphates", Stud. Surf. Sci. Catal., 135, 2128-2135 (2001).

C.J. Fontenot, J.W. Wiench, M. Pruski and G.L. Schrader, "Vanadia Gel Synthesis via Peroxovanadate Precursors. 2. Characterization of the Gels", J. Phys. Chem. B, 105, 10496-10504 (2001).

C. Fernandez, C. Morais and M. Pruski, "Comment on "²⁷Al ³¹P 3QMAS/HETCOR Experiment in Aluminophosphate Molecular Sieves" [Phys. Chem. Chem. Phys., 2000, 2, 5737-5742]", Phys. Chem. Chem. Phys., 3, 2552-53 (2001).

B. Tischendorf, J.U. Otaigbe, J.W. Wiench, M. Pruski and B.C. Sales, "A Study of Short and Intermediate Range Order in Zinc Phosphate Glasses", J. Non-Cryst. Solids,282, 147-158 (2001).

H.J. Kim, M. Pruski, J.W. Wiench, D.Y. Jeong and S.H. Choh, "High Temperature Phase Transitions in LiRbSO₄ studied by Magic Angle Spinning and Multiple Quantum Magic Angle Spinning NMR of 87Rb", Phys. Rev. B, 63, 064107/1-064107/6 (2001).

A. Bailly, J.-P. Amoureux, J.W. Wiench and M. Pruski, "Structural Analysis of ZON-type Aluminophosphates by Solid-State NMR", J. Phys. Chem. B, 105, 773-776 (2001).

C.J. Fontenot, J.W. Wiench, M. Pruski and G.L. Schrader, "Vanadia Gel Synthesis via Peroxovanadate Precursors. 1. In Situ Laser Raman and ⁵¹V NMR Characterization of the Gelation Process", J. Phys. Chem. B, 104, 11622-11631 (2000).

M. Pruski, J. Wiench and J.-P. Amoureux, "On the conversion of triple to single quantum coherences in MQMAS NMR", J. Magn. Reson., 147, 286-295 (2000).

J.W. Wiench, M. Pruski, B. Tischendorf, J.U. Otaigbe and B.C. Sales, "Structural Studies of Zinc Phosphate Glasses by Nuclear Magnetic Resonance", J. Non-Cryst. Solids, 263&264, 101-110 (2000).

D.P. VanderWiel, M. Pruski and T.S. King, "A Kinetic Study on the Adsorption and Reaction of Hydrogen over Silica-Supported Ruthenium and Silver-Ruthenium Catalysts during the Hydrogenation of Carbon Monoxide", J. Catal., 188, 186-202 (1999).

F. Taulelle, M. Pruski, J.-P. Amoureux, D.P. Lang, A. Bailly, C. Huguenard, M. Haouas, C. Gerardin, T. Loiseau and G. Ferey, "Isomerization of the Pre-Nucleation Building Unit during Crystallization of AlPO₄-CJ2. An MQMAS, CP-MQMAS and HETCOR NMR Study", J. Am. Chem. Soc., 121, 12148-12153 (1999).

P.R. Bodart, J.-P. Amoureux, M. Pruski, A. Bailly, and C. Fernandez, "Applications of ²⁷Al Multiple Quantum Magic Angle Spinning NMR to Aluminophsphate Molecular Sieves", Magn. Reson. Chem., 37, 69-74 (1999).

M. Pruski, A. Bailly, D.P. Lang, J.-P. Amoureux and C. Fernandez, "Studies of Heteronuclear Dipolar Interactions Between Spin-1/2 and Quadrupolar Nuclei by Using REDOR During Multiple Quantum Evolution", Chem. Phys. Lett., 307, 35-40 (1999).

M. Pruski, C. Fernandez, D.P. Lang and J.-P. Amoureux, "Measurement of Interatomic Connectivities in Molecular Sieves Using MQMAS-based Methods", Catalysis Today, 49, 401-409 (1999).

C. Fernandez, D.P. Lang, J.-P. Amoureux and M. Pruski, "Measurement of Heteronuclear Dipolar Interactions Between Quadrupolar and Spin-1/2 Nuclei in Solids by Multiple-Quantum REDOR NMR", J. Am. Chem. Soc., 120, 2672-2673 (1998).

S.-J. Hwang, C. Fernandez, J.-P. Amoureux, J.-W. Han, J.-W. Cho, S.W. Martin, and M. Pruski, "Structural Study of xNa₂S - (1-x)B₂S₃ Glasses and Polycrystals by Multiple-Quantum MAS NMR of ¹¹B and ²³Na", J. Am. Chem. Soc., 120, 7337-7346 (1998).

J.-P. Amoureux, D.P. Lang, M. Pruski and C. Fernandez, "Rotational Effects Induced During RF Pulses in MQMAS", J. Magn. Reson., 131, 170-175 (1998).

N. Savargaonkar, R.L. Narayan, M. Pruski, D.O. Uner and T.S. King, "Structure Sensitive Hydrogen Adsorption: Effect of Ag on Ru/SiO₂ Catalysts", J. Catal., 178, 26-33 (1998).

N. Savargaonkar, B.C. Khanra, M. Pruski and T.S. King, "Response to 'Comment on ≈eInfluence of Hydrogen Chemisorption on the Surface Composition of Pt-Rh/Al₂O₃ Catalysts' by J.J. van der Klink and J.-Ph. Ansermet", J. Catal., 170, 213 (1997).

C. Fernandez, L. Delevoye, J.-P Amoureux, D.P. Lang, and M. Pruski, "²⁷Al{¹H} Cross Polarization Triple-Quantum Magic Angle Spinning NMR", J. Am. Chem. Soc.,  119, 6858-6862 (1997).

L.-F. Rao, M. Pruski, and T.S. King, "Structure and Stability of Rhodium Clusters in NaY Studied by NMR and FTIR", J. Phys. Chem. B, 101, 5717-5724 (1997).

D.O. Uner, N. Savargaonkar, M. Pruski, and T.S. King, "The Effects of Alkali Promoters on the Dynamics of Hydrogen Chemisorption and Syngas Reaction Kinetics on Ru/SiO₂ Surfaces", Stud. Surf. Sci. Catal., 109, 315-324 (1997).

S.-J. Hwang, C. Fernandez, J.-P. Amoureux, J. Cho, S.W. Martin, and M. Pruski, "Quantitative Study of the Short Range Order in B₂O₃ and B₂S₃ by MAS and Two-Dimensional Triple-Quantum MAS ¹¹B NMR", Solid State NMR, 8, 109-121 (1997).

M. Pruski, D.P. Lang, C. Fernandez, and J.-P. Amoureux, "Multiple-Quantum Magic-Angle Spinning NMR with Cross-Polarization: Spectral Editing of High Resolution Spectra of Quadrupolar Nuclei", Solid State NMR, 7, 327-331 (1997).

N. Savargaonkar, B.C. Khanra, M. Pruski and T.S. King, "Influence of Hydrogen Chemisorption on the Surface Composition of Pt-Rh/Al₂O₃ Catalysts", J. Catal., 162, 277-283 (1996).

R.L. Narayan, N. Savargaonkar, M. Pruski and T.S. King, "Hydrogen Chemisorption and Mobility on Ru/SiO₂, K/Ru/SiO₂ and Ru-Ag/SiO₂", Studies in Surface Science and Catalysis,101, 921-930 (1996).

L.-F. Rao, S.-J. Hwang, T.S. King, M. Pruski, "Characterization of CO in Rh₆(CO)₁₆/NaY Clusters and Isolated Rh⁺(CO)₂/NaY by Solid-State ¹³C NMR Spectroscopy", J. Phys. Chem., 100, 5668-5671 (1996).

U. Schwerk, D. Michel, and M. Pruski, "Local Magnetic Field Distribution in a Polycrystalline Sample Exposed to a Strong Magnetic Field", J. Magn. Reson. 119A, 157-164 (1996).

M. Pruski, "Supported Metal Catalysts", Encyclopedia of Magnetic Resonance, Ed. D. M. Grant and R. K. Harris, Vol. 7 p. 4636-48, John Wiley & Sons Ltd., (1996).

M. Pruski, "Cokes", Encyclopedia of Nuclear Magnetic Resonance, Ed. D. M. Grant and R. K. Harris, Vol. 2, p. 1378-83, John Wiley & Sons Ltd., (1996).

S.-J. Hwang, D.O. Uner, T.S. King, M. Pruski, and B.C. Gerstein, "Characterization of Silica Catalyst Supports by Single and Multiple Quantum Proton NMR Spectroscopy", J. Phys. Chem., 99, 3697-3703 (1995).

T. Komaya, A.T. Bell, Z. Weng-Sieh, R. Gronsky, F. Engelke, T.S. King, and M. Pruski, "Effects of Sodium on the Structure and Fischer-Tropsch Synthesis Activity of Ru/TiO₂", J. Catal., 152, 350-359 (1995).

M. Pruski, J. Shinar, D.P. Lang, S.-J. Hwang, and H. Jia, "Solid State NMR Studies of Thin Diamond Films", Prep. Pap. - Am. Chem. Soc., Petrol. Chem. 40, 185-186 (1995).

D.O. Uner, M. Pruski, and T.S. King, "Optimization of the Volumetric Hydrogen Chemisorption Technique for Dispersions of Ru/SiO₂ Catalysts", J. Catal., 156, 60-64 (1995).

D.O. Uner, M. Pruski, and T.S. King, "The Role Alkali Promoters in Fisher-Tropsch Synthesis on Ru/SiO₂ Surfaces", Topics in Catalysis, 2, 59-69 (1995).

T. Komaya, A.T. Bell, Z. Weng-Sieh, R. Gronsky, F. Engelke, T.S. King, and M. Pruski, "Effects of Dispersion and Metal-Metal Oxide Interactions on Fischer-Tropsch Synthesis over Ru/TiO₂ and TiO₂-Promoted Ru/SiO₂", J. Catal., 150, 400-406 (1994).

J. Shinar, M. Pruski, D.P. Lang, S.-J. Hwang, and H. Jia, "On the Structure of Thin Diamond Films: A ¹H and ¹³C Nuclear Magnetic Resonance Study", in "Diamond, SiC and Nitride Wide Bandgap Semiconductors", Ed. by C.H. Carter Jr., G. Gildenblat, S. Nakamura, and R.J. Nemanich, Mat. Res. Soc. Symp. Proc. Ser., 339, 675-680 (1994).

J. Shinar, H. Jia, D.P. Lang, and M. Pruski, "On the Nature of the Native Defect ESR in Thin Diamond Films", in "Diamond, SiC and Nitride Wide-Bandgap Semiconductors", Ed. by C.H. Carter Jr., G. Gildenblat, S. Nakamura, and R.J. Nemanich, Mat. Res. Soc. Symp. Proc. Ser., 339, 669-674 (1994).

T. Komaya, A.T. Bell, Z. Weng-Sieh, R. Gronsky, F. Engelke, T.S. King, and M. Pruski, "The Influence of Metal-Support Interactions on the Accurate Determinaton of Ru Dispersion for Ru/TiO₂", J. Catal., 149, 142-148 (1994).

S. Bhatia, F. Engelke, M. Pruski, and T.S. King, "In Situ NMR Studies of Hydrogen Interaction with Supported Ru-group Ib Bimetallic Catalysts", Catalysis Today, 21, 129-140 (1994).

F. Engelke, R. Vincent, T.S. King, and M. Pruski, "Adsorption, Desorption, and Interparticle Motion of Hydrogen on Silica-Supported Ruthenium: A Study by In Situ Nuclear Magnetic Resonance", J. Chem. Phys., 101, 7262-7272 (1994).

K. Erdmann, W. czerwinski, B.C. Gerstein and M. Pruski, "Structural Studies of Poly(Paraphenylene), Poly(2,5-Thienylene) and Their Derivatives by Solid-State NMR of ¹H and ¹³C", J. Polym. Sci. B, Polym. Phys., 32, 1961-1969 (1994).

S. Bhatia, F. Engelke, M. Pruski, B.C. Gerstein and T.S. King, "Interaction of Hydrogen with Supported Ru Catalysts: High Pressure In Situ NMR Studies", J. Catal., 147, 455-464 (1994).

D.O. Uner, M. Pruski, B.C. Gerstein and T.S. King, "Hydrogen Chemisorption on Potassium Promoted Supported Ruthenium Catalysts", J. Catal., 146, 530-536 (1994).

M. Pruski, D.P. Lang, S.-J. Hwang, H. Jia, and J. Shinar, "Structure of Thin Diamond Films: A ¹H and ¹³C Nuclear Magnetic Resonance Study", Phys. Rev. B, 49, 10635-10641 (1994).

D. Michel, M. Pruski and B.C. Gerstein, "NMR of Petroleum Cokes I: Relaxation Studies and Quantitative Analysis of Hydrogen by Magnetic Resonance", Carbon, 32, 31-40 (1994).

M. Pruski, D. Michel and B.C. Gerstein, "NMR of Petroleum Cokes II: Studies by High Resolution Solid-State NMR of ¹H and ¹³C", Carbon, 32, 41-49 (1994).

F. Engelke, S. Bhatia, T.S. King and M. Pruski, "Dynamics of Hydrogen at the Surface of Supported Ruthenium", Phys. Rev. B, 49, 2730-2738 (1994).