Surface Engineering of Cr-Doped Cobalt Molybdate toward High-Performance Hydrogen Evolution

Abstract

Replacing commercial noble metal catalysts with earth-abundant metal catalysts for hydrogen production is an important research direction for electrolytic water. Improving the catalytic performance of non-noble metals while maintaining stability is a key challenge for alkaline hydrogen evolution. Herein, we combined alkali etching and surface phosphating to regulate the properties of Cr-doped CoMoO4 material, forming a surface structure in which amorphous cobalt phosphate and Cr-doped Co­(Mo)­O x coexist. As expected, the as-prepared catalytic material exhibits remarkable hydrogen evolution activity in 1.0 M KOH, only requiring a low overpotential of 52.7 mV to achieve a current density of 10 mA cm–2, and can maintain this current density for 24 h. The characterization and analysis of the catalyst before and after the stability test reveal that the Cr doping and surface engineering (i.e., alkali etching and phosphating) synergistically increase the adsorption and dissociation of water, optimize the desorption of H, and ultimately accelerate hydrogen evolution. This work provides a new strategy for tailoring nonprecious metal materials to improve the hydrogen production from water electrolysis.

Hydrogen production by traditional and novel alkaline water electrolysis on nickel or iron based electrocatalysts

“…In terms of HER catalysts, with abundant reserves and relatively low price, transition metals are expected to replace Pt-based precious metals as promising HER catalysts in large-scale applications. Researchers have conducted extensive research on transition metal alloy catalysts, such as Ni, 68 Co, 69,70 Cr, 71,72 Fe, 73,74 etc. Among them, the NiMo-based catalysts receive the most extensive attention due to their high activity.…”

Anchored RuSe2nanospheres on Co–N–C nanosheets boost electrocatalytic alkaline hydrogen evolution

“…[1][2][3][4] Water electrolysis is an effective strategy to obtain high quality hydrogen. [5][6][7][8] In the past decades, Pt-based electrocatalysts with excellent performance in alkaline media have been considered suitable HER catalysts for water electrolysis. [9][10][11][12] However, high cost and limited reserves greatly restrict the application of Pt-based catalysts.…”

One-Step Electrodeposition of NiMoP/NF as an Efficient and Cost-Effective Cathodic Electrocatalyst for Alkaline Water Electrolysis

“…Although many studies have been conducted on decreasing the doping amount of rare and precious metals like Pt, Pd, and Ir, and the properties of these materials also have shown excellent performance, − the nonrenewable and scarce precious metals are still difficult to produce and use on a large scale. Transition metals, such as Ni, Mo, Fe, Co, and so on, have rich content, the alloy formed by each other, − and the transition metal-based compounds formed with P, B, S, N, and other elements have excellent electrolytic water hydrogen evolution performance − and will eventually become a substitute for precious metals . Among the transition metal-based compounds, numerous studies have proved that transition metal-based phosphates (TMPs) have excellent activity, abundant active sites, and long-term stability .…”