Study On Synthsis Of Nickel Nanoparticles Supported On 2D Layered Carbonaceous Materials Catalysts For Hehydrogenation Of Formic Acid

As a clean and efficient energy,hydrogen is considered as an ideal substitute for traditional fossil fuel energy.Formic acid is a non-toxic,safe,convenient and renewable liquid organic hydrogen carrier,which is become as a promising hydrogen storage material.In the formic acid catalytic dehydrogenation system,homogeneous catalysts are difficult to recycle,in addition,noble metal heterogeneous catalysts are expensive,which limits application in industrial production.Therefore,more and more attention has been devoted to the design and synthesis of catalysts with satisfying performance and at low cost.In this research,the supported nano-catalysts were synthesized with highly conductive two-dimensional Ti3C2 and graphene(GO)acted as supports and transition metal nickel acting as active component.The regulatory mechanism was investigated between the catalyst structure and the catalytic performance in the reaction of FA dehydrogenation.The detailed research results are shown as follows:1.Ni/Ti3C2 catalyst was synthesized by simple hydrothermal and high-temperature calcination method with two-dimensional Ti3C2 as support.The composite could catalyze and decompose formic acid into hydrogen in the reaction solution without other additives.Ti3C2 has a stable layered structure and excellent conductivity,which is beneficial to the electron transport in catalytic reaction.After hydrothermal and calcination treatment,Ni nanoparticles were loaded on the surface and slit of Ti3C2.Due to the synergistic effect,Ni/Ti3C2 catalyst could catalyze formic acid dehydrogenation at near room temperature and presented good performance.2.The surface electronegativity of graphene oxide can adsorb nickel ions in solution and then self assemble Ni(HCO3)2@RGO composite in hydrothermal process.High temperature calcination makes nickel nanoparticles embedded in graphene sheets,and Ni@xRGO with sandwich structure was formed by Ni-C bond.The formation process of Ni@xRGO catalyst and its catalytic mechanism in formic acid dehydrogenation were thoroughly analyzed by studying the effects of calcination temperature and amount of graphene on the morphology and reaction performance of the catalyst.The results proved that the Ni@xRGO catalyst prepared by hydrothermal and calcination method had good catalytic performance.The characterization results showed that different calcination temperatures had great influence on the morphology of the composites,and the calcination temperature of 650℃ was beneficial to the formation of sandwich structure between nickel nanoparticles and graphene materials.Ni@0.20RGO had the highest hydrogen production rate(239.99 mL·g-1·h-1)at 50℃.From the results,the Ni-C bond in the composite material could improve the electron transport rate,and promoted the key steps in the process of hydrogen production by catalytic decomposition of formic acid,and therefore improving the dehydrogenation rate of the catalyst.