Dynamically Structure-Evolved Ultrathin Layered Double Hydroxide Nanosheets for Highly Efficient 5-(hydroxymethyl)furfural Oxidation

The rising global challenge in energy and environmental fields has prompted intensive research on renewable energy conversion and energy storage systems. With decades of endeavors, renewable energy-powered electrocatalytic generation of hydrogen from water has been considered a promising next-generation energy portfolio; nevertheless, the mass commercialization of water electrolyzers is severely hindered by relative sluggish kinetics on the anode and the shortened lifetime of the membrane due to reactive oxygen. To this end, biomass oxidation reaction (BOR), which converts biomass substrates into sustainable fuels and value-added chemical products, has been proposed as an effective alternative to replacing oxygen evolution reaction (OER) for increased efficiency of sustainable hydrogen production.<br/><br/>To inhibit the competing OER and realize the much-facilitated energy conversion, an exceedingly lower onset potential for BOR is strongly desired. Given the tremendous advances in material development, ultrathin two-dimensional (2D) layered double hydroxides (LDHs) are rapidly emerging as a prominent family of catalytic materials displaying lower onset potential for BOR. This is mainly ascribed to their easily regulated electronic and interfacial structures, abundant accessible active sites, large specific surface areas, and preferable electron transfer. On the other hand, the ultrathin 2D material systems generally offer sufficient active sites to collect strong <i>operando</i> spectroscopy signals, which are inherently beneficial to in-depth catalytic mechanism exploration and active site understanding. Consequently, a series of nickel-based ultrathin LDH nanosheets were innovatively constructed by a simple wet-chemistry synthesis strategy to efficiently convert 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA).<br/><br/>This poster will focus on work in the conversion of HMF to FDCA using ultrathin 2D NiFe LDHs and Jahn-Teller distorted ultrathin 2D NiMn LDHs. In view of abundant oxygen defects, a remarkably enlarged potential window and a high faradic efficiency (FE) of nearly 100% for HMF oxidation are accomplished. The judicious employment of X-ray techniques to build up a comprehensive and in-depth understanding of 2D material-based catalytic systems was highlighted in this poster. Specifically, <i>ex-situ</i> X-ray techniques were implemented to investigate the catalytic materials’ atomic-scale structures and electronic structural characteristics; meanwhile, <i>in-situ</i> X-ray techniques were adopted to track the dynamic structural evolution of catalysts in real-time under diverse operating conditions. This presented work is anticipated to offer new insights into the development and application of ultrathin 2D materials as high-performance electrocatalysts in hybrid water electrolysis systems for efficient sustainable-energy generation and large-scale production of fuels and industrially significant chemicals.