Constructing a high concentration CuO/CeO_(2) interface for complete oxidation of toluene:The fantastic application of spatial confinement strategy

In this paper,CeO_(2) substrate was prepared by the sol-gel method,further CuO was introduced by adding the copper complexes with chelating agents into the sol-gel precursors of CeO_(2),in which different chelating agents(β-cyclodextrin,glucose and trimesic acid)were tried.This synthesis method helps the CuO species to disperse very uniformly in the CeO_(2) substrates.When the amount of copper oxide is up to33 mol%,the CuO/CeO_(2) samples can still maintain a highly dispersed state.The CeO_(2) and CuO/CeO_(2)samples were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),X-ray photoelectron spectroscopy(XPS),temperature-programmed reduction of hydrogen(H_(2)-TPR),temperature-programed desorption(O_(2)-TPD),etc.It is found that the CuO/CeO_(2) catalyst prepared byβ-cyclodextrin(βCuO/CeO_(2)) exhibits better catalytic performance owing to the higher dispersion,higher specific surface area,more defects,more active Ce3+and Cu^(+) ions,more oxygen vacancies,more surface active oxygen,relatively better low temperature reducibility,and the exposed(110) active facets.In the condition of 1000×10-6toluene in air and WHSV=60000 mL/(g·h),the T90for toluene conversion is 227℃.The reaction mechanism of toluene catalytic oxidation over CeO_(2)andβCuO/CeO_(2) is discussed by the study of in-situ DRIFTS.This work affords a simple and efficient method for the synthesis of highly dispersed bimetal oxide catalysts with high contents.

Tea-derived carbon materials as anode for high-performance sodium ion batteries

Sodium-ion batteries(SIB) have attracted widespread attention in large-scale energy storage fields owing to the abundant reserve in the earth and similar properties of sodium to lithium. Biomass-based carbon materials with low-cost, controllable structure, simple processing technology, and environmental friendliness tick almost all the right boxes as one of the promising anode materials for SIB. Herein, we present a simple novel strategy involving tea tomenta biomass-derived carbon anode with enhanced interlayer carbon distance(0.44 nm) and high performance, which is constructed by N,P co-doped hard carbon(Tea-1100-NP) derived from tea tomenta. The prepared Tea-1100-NP composite could deliver a high reversible capacity(326.1 m Ah/g at 28 m A/g), high initial coulombic efficiency(ICE = 90% at 28 m A/g),stable cycle life(262.4 m Ah/g at 280 m A/g for 100 cycles), and superior rate performance(224.5 m Ah/g at 1400 m A/g). Experimental results show that the excellent electrochemical performance of Tea-1100-NP due to the high number of active N,P-containing groups, and disordered amorphous structures provide ample active sites and increase the conductivity, meanwhile, large amounts of microporous shorten the Na+diffusion distance as well as quicken ion transport. This work provides a new type of N,P co-doped high-performance tomenta-derived carbon, which may also greatly promote the commercial application of SIB.