Gang Xu,Chenyu Chen,Mengxia Li,Xinyi Ren,Lianggao Hu,Chengrong Wu,Yu Zhuang,Fanan Wang
The electrocatalytic HMF oxidation reaction (HMFOR) is one of the promising technologies for the valorization of biomass derivatives and potential replacements for the energy-consuming oxygen evolution reaction (OER). For the most investigated Ni-based electrode, the in situ reconstruction from Ni(OH)2 to NiOOH is hardly avoidable during the electro-oxidation reaction, which is also a highly indispensable prerequisite towards HMFOR. Herein, we developed an efficient strategy of sacrificing W to investigate the effect of surface defects on the self-reconstruction of Ni for promoting HMFOR. It was rationalized that the selective and rapid exsolution of the W species from the as-prepared NiW layer created a porous structure and induced lattice defects on the surface, which facilitated the ion and electron transportation, and further promoted the in situ reconstruction for the formation of higher oxidated Ni with superior activity for HMFOR. This work offers a novel and low-cost means to enrich the active sites for the electrocatalytic upgrading of HMF and other bio-derived platforms.
Yanwei Zhu,Jianqiao Shi,Yingying Li,Yuxuan Lu,Bo Zhou,Shuangyin Wang,Yuqin Zou
Surface segregation is ubiquitous in multi-component materials and is of great important for catalysis but little is known on the surface structure under graphene encapsulation. Here, we show that the graphene encapsulated CoCu performs well for the electrocatalytic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) with the onset potential before 1.23 V RHE and a nearly 100% selectivity of FDCA under 1.4 V RHE . From the experimental results, the unprecedented catalytic performance was attributed to local structural distortion and sub-nanometer lattice composition of the CoCu surface. We accurately show the dispersed Cu doped Co 3 O 4 nano-islands with a lot of edge sites on the bimetallic Co-Cu surface. While, the gradient components effectively facilitate the establishment of built-in electric field and accelerate the charge transfer. Theoretical and experimental results reveal that the surface Co and neighbouring Cu atoms in sub-nanometer lattice synergistically promote the catalysis of HMF. This work offers new insights into surface segregation in tuning the element spatial distribution for catalysis.