Design And Perforemance Exploration Of LDH-based Nanomaterials In Solar-driven Methane Conversion

How to efficiently develop and utilize renewable energy is a challenging problem in today’s society,which is of great significance for alleviating the current energy crisis,controlling serious environmental pollution,promoting rapid development of national economy and further realizing sustainable utilization of resource.In this paper,we took efficient conversion of methane(CH4)under mild conditions as the starting point,combining with the characteristics of layered double hydroxides(LDHs),using it as a carrier or precursor,a series of catalysts with high performance and selectivity in solardriven CH4 conversion were prepared,which realized the high efficiency and selective preparation of hydrogen(H2)/ethane(C2H6).The combination of experiment and in-situ characterization technology was used to inquiry the microstructure of the catalyst and reveal its influence on the reaction performance.The research contents and results are as follows:1.In view of the high temperature,poor catalytic activity,rapid deactivation due to carbon deposition of the catalyst in the preparation of H2 from solar-driven CH4,a liquid-phase reduction method was used to synthesize a Ni-based catalyst with full-band solar spectra absorption capacity.The photothermal catalytic CH4 steam reforming to H2 was performed at a rate of 388.28 μmol·g-1·min-1.Further,the solar light was directly used as the only external source to test the H2 production performance,showing good H2 production performance,and the rate was 668.76 μmol·g-1·min-1.The good H2 production performance was attributed to the highly dispersed metallic Ni,which laid a foundation for the direct application of solar energy activated CH4 to produce H2.2.In view of the problems of poor selectivity,high reaction temperature and complex equipment for preparing high value-added products by CH4 coupling,taking advantage of the advantage of LDHS topological transformation to prepare mixed metal oxides(MMO)with rich interfaces and defective structures,ZnMgAl-LDH was used as precursor to obtain heterogeneous catalysts MgO/ZnO/Al2O3 by changing the calcination temperature.It has high selectivity in the reaction of CH4 to C2H6,and can completely inhibit its peroxidation to CO2.The fine structure characterization showed that the large specific surface area was favorable for the adsorption of the reactants,and the highly exposed MgO(110)crystal plane and the oxygen defect(Vo)could effectively improve the photogenerated charge transfer/transport.This work provides a new idea for the highly selective conversion of CH4.