Anionic Regulation and Heteroatom Doping of Ni‐Based Electrocatalysts to Boost Biomass Valorization Coupled with Hydrogen Production

Abstract

Electrocatalytic biomass valorization coupled with hydrogen production provides an efficient and economical way to achieve a zero‐carbon economy. Ni‐based electrocatalysts are promising candidates due to their intrinsic redox capabilities, but the rational design of active Ni site coordination is still a huge challenge. Herein, the combined strategies of surface reconstruction and heteroatom doping are adopted to modify Ni3S2 pre‐catalysts and the obtained bimetallic catalyst exhibits superior electrocatalytic performance toward 5‐hydroxymethylfurfural (HMF) oxidation to 2,5‐furanedicarboxylic acid (FDCA). Specifically, the oxysulfide‐coordinated amorphous NiOOH (NiOOH‐SOx) active phase is in situ constructed following the anionic regulation mechanism, which endows numerous defects and unsaturated sites for anodic HMF oxidation. Cu heteroatom doping further modulates the electronic structure of active sites with abundant Lewis acidic sites, offering advanced capability for HMF adsorption. Several operando characterization techniques (in situ Raman, infrared, and electrochemical impedance spectroscopies) are performed to disclose the reaction pathway and structure‐activity‐potential relationship. Theoretical results further demonstrate that Cu doping and oxyanionic regulation effectively modulate the local coordination environment of Ni sites and correspondingly tailor the intermediate adsorption behavior and then promote the reaction kinetics. Moreover, a two‐electrode system is assembled to pair HMF oxidation with cathode hydrogen production, demonstrating better energy conversion efficiency.

Modulating Ni–S coordination in Ni3S2 to promote electrocatalytic oxidation of 5-hydroxymethylfurfural at ampere-level current density

“…Besides, there was an extra peak assigned to the Ni–S bond at 852.3 eV. 30,33 More importantly, the binding energy of Ni 2p increased with the increase of the water ratio in the solvothermal system, suggesting that the Ni sites in the Ni 3 S 2 /NF were more negatively charged. In the XPS spectra of S 2p, two peaks at 162.1 eV and 163.5 eV, which were assigned to S 2− 2p 3/2 and S 2− 2p 1/2 , respectively, could be observed.…”

Recent Advances in Electrocatalytic Oxidation of 5-Hydroxymethylfurfural to 2,5-Furandicarboxylic Acid by Heterogeneous Catalysts

“…Recently, Zheng and co-workers used the strategy of combining surface reconstruction and heteroatom doping (Cu, Fe, V, and Zn) to modify the Ni 3 S 2 precatalyst to prepare a series of M/Ni 3 S 2 -R catalysts (Figure 8) [52]. It was found that Cu 2+ (3d 9 ) with its unique electronic structure provided abundant Lewis acid sites for HMF adsorption.…”