Intense Microwave Heating at Strongly Polarized Solid Acid/water Interface for Energy-efficient Platform Chemical Production

Microwave hot spots at strongly polarized solid/liquid interface drive energy-efficient dehydration reactions [Display omitted] •TiO2 structure control maximizes the density of active center and degrees of interfacial polarization.•Strongly polarized solid/liquid interface promotes reaction energy efficiency under microwave.•10 times higher energy efficiency was achieved than commercial TiO2 in fructose dehydration reaction.•Surface sulfonic group polarizes surface water molecules and acts as “hot-spots” to accelerate reaction. A strongly polarized solid/liquid interface is constructed to create a “micro-hydrothermal” environment under microwave and promote reaction energy efficiency. Specifically, TiO2 with open crystal structure was synthesized to maximize the density of surface-active centers and the degrees of interfacial polarization. Acidic groups were grafted on the catalyst surface, which served as catalytically active sites as well as heat-generation spots under microwave irradiation. Benefited by enhanced interfacial polarization, 10 times higher energy efficiency (6.8 mmol (kJ L)-1) than commercial TiO2 can be achieved in fructose dehydration reaction. MD simulation revealed that sulfonic group polarized surface water molecules and acted as “hot-spots” to accelerate fructose dehydration to HMF. Such alignment of site-specific heating and reaction by material design has great potential to shift the energy efficiency for a wide range of chemical reactions.