Nonprecious Bimetallic Iron–Molybdenum Sulfide Electrocatalysts for the Hydrogen Evolution Reaction in Proton Exchange Membrane Electrolyzers

Abstract

In this study, we report the synthesis and characterization of non-precious bimetallic ironmolybdenum sulfide bioinspired electrocatalysts for the hydrogen evolution reaction (HER).Iron-molybdenum sulfide materials were obtained through three distinct scalable synthetic approaches using microwave irradiation or heat treatment in furnace under inert and reductive atmospheres. These electrocatalysts were combined with carbon nanotubes (CNTs) and their activity for the hydrogen evolution reaction (HER) was studied in acidic environment. The most efficient composite material of the series was obtained by microwave synthesis and displays a current density per geometric area of 10 mAcm -2 at an overpotential of 140 mV with unity faradaic efficiency for hydrogen evolution. This composite cathode catalyst was implemented into a proton exchange membrane (PEM) electrolyzer single cell with iridium black as anode catalyst and could be operated at 0.5 Acm -2 requiring less than 300 mV additional voltage compared to Pt, and with remarkable stability during accelerated stress testing.PEM-compatible oxygen evolution reaction (OER) catalysts based on Earth-abundant elements. [99][100] ASSOCIATED CONTENT Supporting Information. Supporting Information. Additional experimental details, PEM electrolyzer setup, SEM images, Raman spectra, XPS spectra, electrochemical results (PDF).

The electronic structure of transition metal oxides for oxygen evolution reaction

“…1 However, the excessive consumption of fossil fuels caused by the rapidly increasing world population and expanding industrialization as well as concomitant environmental problems have motivated our society to explore a green and sustainable energy system for long-term development. [2][3][4][5] In this regard, countries around the world have made gigantic efforts to raise the share of renewable and carbon-free sources of energy, such as solar, wind, and tidal energy. 6 Unfortunately, these energy sources have a general intermittent availability and heavily depend on the season and weather, which result in a low energy delivery efficiency and Hongxia Wang received her master degree in chemistry and chemical engineering from Chongqing University in 2020.…”

Acid‐durable, high‐performance cobalt phosphide catalysts for hydrogen evolution in proton exchange membrane water electrolysis

“…The overpotentials at 10 mA/cm 2 increase in the order of Co-P-0.3 (143.85 mV) < Co-P-0.2 (167.11 mV) < Co-P-0.4 (171.59 mV) < Co-P-0.1 (227.38 mV) < Co-P-0.5 (280.89 mV) < Co-P-0.6 (345.98 mV) < Co (346.27 mV), exhibiting a volcano-like trend and showing the best HER performance for Co-P-0.3, that is, Co 94 P 6 . When compared with commercial Pt-based catalysts and others, the lowest overpotential of 143.85 mV in the case of Co-P-0.3 was still higher than those of Pt/C on Ti (14 mV), 32 Pt/C on CP (10 mV), 77 NiS 2 -Ni(OH) 2 (90 mV), 78 and MoS x /Ni-metalorganic framework-74 (114 mV) 79 but comparable to other non-PGM catalysts such as CoP (130 mV), 80 FeMoS (140 mV), 81 and N, P-dual-doped MoS 2 (147 mV) 82 and even better than [Mo 3 S 13 ] 2À (188 mV), 50 MoS 2 (190 mV), 83 NbS 2 (207 mV), 84 CoCu (342 mV), 27 and VS 2 (350 mV). 85 In addition, the Tafel slopes of each catalyst at the fourth cycle (Figure 5H) exhibit the same volcano-like trend, showing the lowest slope of 60.10 mV/dec for Co-P-0.3 (Co 94 P 6 ), which is comparable to results obtained previously for Co-P, that is, Tafel slopes from 45 to 82 mV/dec.…”

Microwave‐Positioning Assembly: Structure and Surface Optimizations for Catalysts

“…It can be defined as the microwave‐positioning assembly synthesis. During this synthesis, the composition or modification of materials can be attributed to the optimization of the structure, [ 4–8 ] components, [ 9 ] defects, [ 10–15 ] surface, [ 16–21 ] interface, and other aspects of the material. For these microwave‐optimized results, the prepared catalytic materials showed significant improvements in many aspects, such as reactant adsorption, photoresponse, carrier transport, interfacial enhancement, and catalytic kinetics.…”