Research Of Catalytic Hydrogenation And Electrocatalytic No_x^- Synthesis Of Ammonia With CuFe LDH Derivatives

Over the past hundred years,the world has ushered in a great explosion of industrial technology,which has led to radical changes in people’s lifestyles,bringing various conveniences,but also leading to a global energy and environmental crisis.Therefore,it is urgent to realize the transformation and green development of the low-carbon energy system.At present,more than 90%of the chemical industry is based on catalysts.Catalysis can reduce the energy barrier of various reactions and achieve more efficient reactions.Therefore,catalytic technology has endless potential in the field of green industry and energy conversion.More efficient,cheaper and greener catalysts could not only facilitate the technological revolution to change the industrial structure,but also enable higher quality output while saving energy.To make the human’s use of natural resources more rational and broader.Improving industrial technology through rational design of catalysts to achieve energy conversion and turning waste-to-treasure is an important approach to sustainable development.Based on the earth’s abundant and inexpensive reserves of the metal Cu,it is possible to effectively replace precious metal catalysts by modulating the size and structure to exhibit varying catalytic activity and generate unique quantum properties,giving copper-based materials unique physicochemical properties.In this paper,the catalysis is based on the excellent activity of copper element,which is supported on iron foam to form layered double hydroxide（LDH）precursor,and the catalytic performance can be improved by further adjusting the synthesis conditions.The details are as follows:（1）Using iron foam as the substrate and participating in the reaction at the same time,the copper and iron are closely combined to the surface through the Fenton reaction to form a layered LDH structure,and with the massive exotherm of the reaction LDH will pyrolyse to generate the corresponding layered bimetallic oxide（LDO）material.The layered LDO material exhibits the morphology and structure of chrysanthemum clusters,exposing many active sites and active specific surface area,which can enhance the catalytic performance through the synergistic effect between the bimetals.It was used as a catalyst for the decomposition of aminoborane and the hydrogenation of tandem nitroaromatic compounds.The experimental data show that LDO achieves efficient ammonia borane（AB）decomposition to produce hydrogen and exhibits good stability.At the same time,the intermediate H*generated by AB decomposition was used for the hydrogenation of nitrobenzene（-NO₂）to form aniline（-NH₂）test,the conversion rate reached 96%in 20min,and the selectivity was higher than 99%.Expanding the substrate range,it also has catalytic activity for some nitroaromatic compounds,and all the conversion rates were above 80%.（2）Using LDO as the precursor material,phosphating at high temperature in a tube furnace to generate the corresponding metal phosphide CuFe-P.The SEM results proved that the precursor’s chrysanthemum cluster structure was maintained,and the flower core was covered with phosphate.A heterostructure is formed between Cu₃P and Fe₂P,which accelerates the transfer of electrons,and the synergistic effect between the bimetals also improves the electrochemical performance.The test of CuFe-P as an electrode material to catalyze NO_x^-reduction to ammonia synthesis shows better performance compared with LDO,which is attributed to the fact that negatively charged P can adsorb a large amount of weakly active H*and transfer H*to the adsorption substrate.The metal surface can realize the conversion of NO_x^-to NH₃,and Cu also inhibits the side reaction HER and reduces the occurrence of competitive reactions.The Faradaic efficiency of e NO₂RR can be as high as 96.96%at-0.1V vs.RHE voltage,and the Faradaic efficiency of e NO₃RR can reach 72.0%at-0.2V vs.RHE.At the same time,the catalyst showed excellent cycle stability in this system.