Surface electronic state mediates concerted electron and proton transfer at metal nanoscale interface for catalytic hydride reduction of −NO2 to −NH2

2021 ◽  
Author(s):  
Bing-Qian Shan ◽  
Jiafeng Zhou ◽  
Meng Ding ◽  
Xiaodan Hu ◽  
Kun Zhang
Keyword(s):  
Proton Transfer ◽  
Electronic State ◽  
Molecular Hydrogen ◽  
Activation Mechanism ◽  
Surface Electronic State ◽  
Hydride Reduction

Concerted electron and proton transfer is a key step for the reversible conversion of molecular hydrogen in both heterogeneous nanocatalysis and metalloenzyme catalysis. However, its activation mechanism involving electron and...

scholarly journals Surface Electronic State Mediates Proton Transfer at Metal Nanoscale Interface for Catalytic Hydride Reduction of −NO2 to −NH2

2021 ◽  
Author(s):  
Bingqian Shan ◽  
Jiafeng Zhou ◽  
Meng Ding ◽  
Xiao-Dan Hu ◽  
Kun Zhang
Keyword(s):  
Proton Transfer ◽  
Electronic State ◽  
Isotope Labeling ◽  
Chem Phys ◽  
Catalyst Design ◽  
Activation Mechanism ◽  
Spectroscopic Techniques ◽  
Surface Electronic State ◽  
Hydride Reduction ◽  
Catalytic Active Site

Concerted electron and proton transfer is a key step for the reversible conversion of molecular hydrogen in both heterogeneous nanocatalysis and metalloenzyme catalysis. (Gabor A. Somorjai, et al. PNAS, 2016, 113, 5159–5166) However, the activation mechanism involving electron and proton transfer dynamic remains elusive. (Starla D. Glover and Leif Hammarström et al., J. Am. Chem. Soc. 2021, 143, 560−576.) With the most widely used catalytic hydride reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) as a model reaction, we evaluate the catalytic activity of noble metal NPs trapped in porous silica in aqueous NaBH4 solution. By virtue of a novel combination of catalyst design, reaction kinetics, isotope labeling, and multiple spectroscopic techniques, we counter-intuitively demonstrates that, the hydrogen resource of the final product of 4-AP by hydride reduction is not originated from the NaBH4 reduced, and that metal NPs (Ag/Pt/Pd) is not a real catalytic active site for surface electron mediation. (Avelino Corma etal., Angew. Chem. Int. Ed. 2007, 46, 7266 –7269; ACS Catal. 2015, 5, 7114−7121.). A completely new ‘Surface Electronic State Mediated Proton Transfer’ mechanism was proposed to understand the catalytic hydride reduction of −NO2 to −NH2 at metal nanoscale interface. The similar concerted electron and proton transfer dynamic was only recently observed in the [FeFe]-hydrogenases for reversible proton reduction. (Gregory A. Voth et al., J. Phys. Chem. B 2013, 117, 4062−4071; J. Chem. Phys. 2014, 141, 22D527; Juan C. Fontecilla-Camps et al., Chem. Rev. 2007, 107, 4273-4303.) We believed that current research provide a completely new insights into the working mechanism of nanocatalysis and metalloenzyme catalysis involved by electron and proton transfer.

scholarly journals Surface Electronic State Mediates Proton Transfer at Metal Nanoscale Interface for Catalytic Hydride Reduction of −NO2 to −NH2

2021 ◽  
Author(s):  
Bingqian Shan ◽  
Jiafeng Zhou ◽  
Meng Ding ◽  
Xiao-Dan Hu ◽  
Kun Zhang
Keyword(s):  
Proton Transfer ◽  
Electronic State ◽  
Isotope Labeling ◽  
Chem Phys ◽  
Catalyst Design ◽  
Activation Mechanism ◽  
Spectroscopic Techniques ◽  
Surface Electronic State ◽  
Hydride Reduction ◽  
Catalytic Active Site

Concerted electron and proton transfer is a key step for the reversible conversion of molecular hydrogen in both heterogeneous nanocatalysis and metalloenzyme catalysis. (Gabor A. Somorjai, et al. PNAS, 2016, 113, 5159–5166) However, the activation mechanism involving electron and proton transfer dynamic remains elusive. (Starla D. Glover and Leif Hammarström et al., J. Am. Chem. Soc. 2021, 143, 560−576.) With the most widely used catalytic hydride reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) as a model reaction, we evaluate the catalytic activity of noble metal NPs trapped in porous silica in aqueous NaBH4 solution. By virtue of a novel combination of catalyst design, reaction kinetics, isotope labeling, and multiple spectroscopic techniques, we counter-intuitively demonstrates that, the hydrogen resource of the final product of 4-AP by hydride reduction is not originated from the NaBH4 reduced, and that metal NPs (Ag/Pt/Pd) is not a real catalytic active site for surface electron mediation. (Avelino Corma etal., Angew. Chem. Int. Ed. 2007, 46, 7266 –7269; ACS Catal. 2015, 5, 7114−7121.). A completely new ‘Surface Electronic State Mediated Proton Transfer’ mechanism was proposed to understand the catalytic hydride reduction of −NO2 to −NH2 at metal nanoscale interface. The similar concerted electron and proton transfer dynamic was only recently observed in the [FeFe]-hydrogenases for reversible proton reduction. (Gregory A. Voth et al., J. Phys. Chem. B 2013, 117, 4062−4071; J. Chem. Phys. 2014, 141, 22D527; Juan C. Fontecilla-Camps et al., Chem. Rev. 2007, 107, 4273-4303.) We believed that current research provide a completely new insights into the working mechanism of nanocatalysis and metalloenzyme catalysis involved by electron and proton transfer.

scholarly journals How [FeFe]-Hydrogenase Facilitates Bidirectional Proton Transfer

2019 ◽  
Author(s):  
Moritz Senger ◽  
Viktor Eichmann ◽  
Konstantin Laun ◽  
Jifu Duan ◽  
Florian Wittkamp ◽  
...  
Keyword(s):  
Amino Acid ◽  
Proton Transfer ◽  
Active Site ◽  
Molecular Hydrogen ◽  
H2 Production ◽  
Amino Acid Residues ◽  
Difference Spectroscopy ◽  
Dynamic Changes ◽  
In Situ Ir

Hydrogenases are metalloenzymes that catalyse the interconversion of protons and molecular hydrogen, H2. [FeFe]-hydrogenases show particularly high rates of hydrogen turnover and have inspired numerous compounds for biomimetic H2 production. Two decades of research on the active site cofactor of [FeFe]-hydrogenases have put forward multiple models of the catalytic proceedings. In comparison, understanding of the catalytic proton transfer is poor. We were able to identify the amino acid residues forming a proton transfer pathway between active site cofactor and bulk solvent; however, the exact mechanism of catalytic proton transfer remained inconclusive. Here, we employ in situ IR difference spectroscopy on the [FeFe]-hydrogenase from Chlamydomonas reinhardtii evaluating dynamic changes in the hydrogen-bonding network upon catalytic proton transfer. Our analysis allows for a direct, molecular unique assignment to individual amino acid residues. We found that transient protonation changes of arginine and glutamic acid residues facilitate bidirectional proton transfer in [FeFe]-hydrogenases.<br>

ChemInform Abstract: Electronic-State Dependence of Intramolecular Proton Transfer of o-Hydroxybenzaldehyde.

ChemInform ◽  
1988 ◽  
Vol 19 (18) ◽  
Author(s):  
S. NAGAOKA ◽  
U. NAGASHIMA ◽  
N. OHTA ◽  
M. FUJITA ◽  
T. TAKEMURA
Keyword(s):  
Proton Transfer ◽  
Electronic State ◽  
State Dependence ◽  
Intramolecular Proton Transfer

scholarly journals Surface electronic state of superconducting topological crystalline insulator

2015 ◽  
Vol 92 (17) ◽  
Author(s):  
Tatsuki Hashimoto ◽  
Keiji Yada ◽  
Masatoshi Sato ◽  
Yukio Tanaka
Keyword(s):  
Electronic State ◽  
Surface Electronic State ◽  
Topological Crystalline Insulator

scholarly journals Importance of resonances in surface-electronic-state spectroscopy: (110) surfaces of ZnSe and ZnTe

1982 ◽  
Vol 26 (2) ◽  
pp. 769-772 ◽  
Author(s):  
Richard P. Beres ◽  
Roland E. Allen ◽  
John D. Dow
Keyword(s):  
Electronic State ◽  
Surface Electronic State
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