In-situ observation of isotopic hydrogen evolution reactions using electrochemical mass spectroscopy to evaluate surface morphological effect

Abstract

In the present article, the hydrogen evolution reaction in the mixed solution of H2O and D2O has been investigated on Pt and Ag electrodes via the electrochemical mass (ECmass) spectroscopy. In addition to the metal species dependence, we have confirmed the morphological effect of the electrode surface on the isotopic effect. By the establishment of the EC-mass system, we have successfully discussed about the formation of the active sites which accelerated the hydrogen generation at the surface of Ag by the surface roughening process. The present results prove the importance of in-situ mass spectroscopic measurement for the investigation to establish the arbitrary control of the isotopic hydrogen evolution reactions.

Advanced Characterization Techniques for Identifying the Key Active Sites of Gas‐Involved Electrocatalysts

“…In addition, electrochemical measurements can also be combined with them to detect surface defects and morphology. Combining electrochemical tests [ 48 ] with mass spectroscopy, differential electrochemical mass spectroscopy (DEMS), is helpful to determine reaction products rapidly. The information obtained from the single technique is limited, but the integration of these advanced techniques is essential to observe easily outlooked points.…”

“…Reproduced with permission. [ 48b ] Copyright 2016, American Chemical Society. f) n‐ECSTM of Pt (111).…”

“…Reproduced with permission. [ 48c ] Copyright 2019, Royal Society of Chemistry. g) ATR‐SERITA of Pd electrode.…”

“…It is also effective in the research of tracking isotope during HER process. [ 48a ] Other recently introduced techniques like selected‐ion flow tube mass spectrometry (SIFT‐MS), surface‐enhanced infrared absorption spectroscopy (SEIRAS), and DEMS are also available to characterize the reaction processes of electrocatalysis. Specifically, SIFT‐MS is integrated with Raman spectroscopy to provide real time analysis on the catalyst surface and generated products, paving the way for the molecular insight of the electrochemical process.…”

“…Appropriate Nb dopant in MoS 2 has been reported to be crucial to improve the CRR activity. [ 48b ] Electrochemical measurements show that 5% Nb doping in vertically aligned MoS 2 (MoS 2 :Nb) delivers one order of magnitude higher CO formation turnover frequency than pristine MoS 2 . As illustrated in Figure a,b, the HAADF‐STEM and ABF‐STEM images demonstrate the hexagonal structure of the as‐prepared materials and atomic arrangements of Nb, Mo, S. Raman further confirms the unchanged crystal structure after doping.…”