Electrocatalytic proton reduction to form dihydrogen (H2) is an effective way to store energy in the form of chemical bonds. In this study, we validate the applicability of a main‐group‐element‐based tin porphyrin complex as an effective molecular electrocatalyst for proton reduction. A PEGylated Sn porphyrin complex (
Electrocatalytic hydrogen gas production is considered a potential pathway towards carbon‐neutral energy sources. However, the development of this technology is hindered by the lack of efficient, cost‐effective, and environmentally benign catalysts. In this study, a main‐group‐element‐based electrocatalyst,
- Award ID(s):
- 2041436
- PAR ID:
- 10371402
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Chemistry – A European Journal
- Volume:
- 28
- Issue:
- 52
- ISSN:
- 0947-6539
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
Abstract SnPEGP ) displayed high activity (−4.6 mA cm−2at −1.7 V vs. Fc/Fc+) and high selectivity (H2Faradaic efficiency of 94 % at −1.7 V vs. Fc/Fc+) in acetonitrile (MeCN) with trifluoroacetic acid (TFA) as the proton source. The maximum turnover frequency (TOFmax) for H2production was obtained as 1099 s−1. Spectroelectrochemical analysis, in conjunction with quantum chemical calculations, suggest that proton reduction occurs via an electron‐chemical‐electron‐chemical (ECEC) pathway. This study reveals that the tin porphyrin catalyst serves as a novel platform for investigating molecular electrocatalytic reactions and provides new mechanistic insights into proton reduction. -
Abstract Electrocatalytic proton reduction to form dihydrogen (H2) is an effective way to store energy in the form of chemical bonds. In this study, we validate the applicability of a main‐group‐element‐based tin porphyrin complex as an effective molecular electrocatalyst for proton reduction. A PEGylated Sn porphyrin complex (
SnPEGP ) displayed high activity (−4.6 mA cm−2at −1.7 V vs. Fc/Fc+) and high selectivity (H2Faradaic efficiency of 94 % at −1.7 V vs. Fc/Fc+) in acetonitrile (MeCN) with trifluoroacetic acid (TFA) as the proton source. The maximum turnover frequency (TOFmax) for H2production was obtained as 1099 s−1. Spectroelectrochemical analysis, in conjunction with quantum chemical calculations, suggest that proton reduction occurs via an electron‐chemical‐electron‐chemical (ECEC) pathway. This study reveals that the tin porphyrin catalyst serves as a novel platform for investigating molecular electrocatalytic reactions and provides new mechanistic insights into proton reduction. -
Abstract The chemical dynamics of the elementary reaction of ground state atomic silicon (Si;3P) with germane (GeH4; X1A1) were unraveled in the gas phase under single collision condition at a collision energy of 11.8±0.3 kJ mol−1exploiting the crossed molecular beams technique contemplated with electronic structure calculations. The reaction follows indirect scattering dynamics and is initiated through an initial barrierless insertion of the silicon atom into one of the four chemically equivalent germanium‐hydrogen bonds forming a triplet collision complex (HSiGeH3;
3 i1 ). This intermediate underwent facile intersystem crossing (ISC) to the singlet surface (HSiGeH3;1 i1 ). The latter isomerized via at least three hydrogen atom migrations involving exotic, hydrogen bridged reaction intermediates eventually leading to the H3SiGeH isomeri5 . This intermediate could undergo unimolecular decomposition yielding the dibridged butterfly‐structured isomer1 p1 (Si(μ‐H2)Ge) plus molecular hydrogen through a tight exit transition state. Alternatively, up to two subsequent hydrogen shifts toi6 andi7 , followed by fragmentation of each of these intermediates, could also form1 p1 (Si(μ‐H2)Ge) along with molecular hydrogen. The overall non‐adiabatic reaction dynamics provide evidence on the existence of exotic dinuclear hydrides of main group XIV elements, whose carbon analog structures do not exist. -
Abstract Reductive hydrodechlorination is an effective approach to enhance the degradation rate of chlorinated herbicides such as alachlor, which are frequently detected in ground and surface water. In this study, a cobalt porphyrin complex with eight triazole units and alkyl chains,
CoPor8T , was synthesized to catalyze the reductive hydrodechlorination of alachlor. Mechanistic study was performed using a combination of voltametric, spectroscopic, and electrospectroscopic techniques. A conversion yield of 84 % at −1.8 V vs. Fc/Fc+and chloride ion concentration of 96 % was obtained after electrocatalysis. This work provides a new avenue of using molecular catalysts for electrocatalytic chlorinated herbicide remediation. -
Abstract In this study, we employed electrochemical‐mass spectrometry (EC‐MS) to elucidate the role of halide anions in electrochemical CO2and CO reduction. We found that the undesired hydrogen evolution reaction (HER) was significantly suppressed by the anion used. Specifically, the rates of H2production decreased in the order KF > KCl > KI, meaning that I−most strongly suppressed HER. Interestingly, CO reduction products showed an inverse relationship to HER, with KI leading to the highest rate of CO reduction. By pairing our experimental findings with classical molecular dynamics simulations, we propose a mechanism wherein halide anions influence the dynamic interplay between CO reduction and HER by modulating the competition of H* and CO* for active sites on the Cu surface. We propose that this interaction is enabled by the interfacial concentration of K+being greater in the presence of F−than in I−. Our results highlight the need to more broadly consider the properties of ions at electrocatalytic interfaces and they point to thus far underappreciated avenues to optimize hydrocarbon production while suppressing hydrogen evolution.