Highly active and stable bifunctional electrocatalysts for overall water splitting are important for clean and renewable energy technologies. The development of energy-saving electrocatalysts for hydrogen evolution reaction (HER) by replacing the sluggish oxygen evolution reaction (OER) with a thermodynamically favorable electrochemical oxidation (ECO) reaction has attracted increasing attention. In this study, a self-supported, hierarchical, porous, nitrogen-doped carbon (NC)@CuCo 2 N x /carbon fiber (CF) is fabricated and used as an efficient bifunctional electrocatalyst for both HER and OER in alkaline solutions with excellent activity and stability. Moreover, a two-electrode electrolyzer is assembled using the NC@CuCo 2 N x /CF as an electrocatalyst at both cathode and anode electrodes for H 2 production and selective ECO of benzyl alcohol with high conversion and selectivity. The excellent electrocatalytic activity is proposed to be mainly due to the hierarchical architecture beneficial for exposing more catalytic active sites, enhancing mass transport. Density functional theoretical calculations reveal that the adsorption energies of key species can be modulated due to the synergistic effect between CoN and CuN. This work provides a reference for the development of high-performance bifunctional electrocatalysts for simultaneous production of H 2 and high-value-added fine chemicals.
Nanoscale inorganic wheel-shaped structures are one of the most striking types of molecular aggregations. Here, we report the synthesis of a gigantic lanthanide wheel cluster containing 140 Gd atoms. As the largest lanthanide cluster reported thus far, {Gd} features an attractive wheel-like structure with 10-fold symmetry. The nanoscopic molecular wheel possesses the largest diameter of 6.0 nm and displays high stability in solution, which allows direct visualization by scanning transmission electron microscopy. The newly discovered lanthanide {Gd} cluster represents a new member of the molecular wheel family.
Paired electrosynthesis is a promising technology with the potential to generate value-added products at both electrodes in a cost-effective manner. Herein, 3D vanadium nitride (VN) and Pd/VN hollow nanospheres are successfully fabricated and coupled to carry out simultaneous electrocatalytic oxidation (ECO) and electrocatalytic hydrogenation (ECH) of 5-hydroxymethylfurfural (HMF) into 2, 5-furandicarboxylic acid (FDCA) and 2,5-bishydroxymethyl-tetrahydrofuran (DHMTHF), respectively. VN shows excellent ECO performance with high HMF conversion (≥98%), FDCA selectivity (≥96%), and faradaic efficiency (≥84%) after a stability test, and Pd/VN achieves high ECH selectivity for DHMTHF at ≥88% and an HMF conversion of ≥90%, with a faradaic efficiency of ≥86%. VN and Pd/VN incorporated into a membrane electrode assembly in a paired electrolysis system shows potential for large-scale biomass conversion and upgrading. Theoretical calculations reveal that the higher performance of VN for the production of ECO can be attributed to its lower d-band center level relative to the Fermi level compared to that of V 2 O 5 , which favors HMF chemisorption and activation. This study paves the way for developing paired electrosynthesis technologies with the potential for biomass utilization and energy conversion.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.