Electrochemical Fixation of Nitrogen and Its Coupling with Biomass Valorization with a Strongly Adsorbing and Defect Optimized Boron–Carbon–Nitrogen Catalyst

The electrochemical conversion of low-cost precursors into high-value chemicals using renewably generated electricity is a promising approach to build up an environmental friendly energy cycle, including a storage element. The large-scale implementation of such process can however only be realized by the design of cost-effective electrocatalysts with high efficiency and highest stability. Here, we report the synthesis of N and B co-doped porous carbons. The constructed B-N motives combine abundant unpaired electrons and Frustrated Lewis pairs (FLPs). They result in desirable performance for electrochemical N2 reduction reaction (NRR) and electrooxidation of 5-hydroxymethylfurfural (HMF) in absence of any metal co-catalyst. A maximum Faradaic efficiency of 15.2% with a stable NH3 production rate of 21.3 µg h-1 mg-1 is obtained in NRR. Besides, 2,5-furandicarboxylic acid (FDCA) is firstly obtained by using non-metal-based electrocatalysts at a conversion of 71% and with yield of 57%. Gas adsorption experiments elucidate the relationship between the structure and the ability of the catalysts to activate the substrate molecules. This work opens up deep insights for the rational design of non-metal-based catalysts for potential electrocatalytic applications and the possible enhancement of their activity by the introduction of FLPs and point defects at grain boundaries.