Study On Preparation And Properties Of Nickle-Based/biochar Composite Nano-catalysts

Caused serious environmental problems greenhouse effect,air pollution and water pollution for CO₂,NOx and SOx and other greenhouse gases from fossil fuel in the combustion process.Thus,this thesis proposes using a low cost,readily available and potatoes,radish,asparagus biomass material for the preparation of a natural biological structure raw carbon material as the carrier material,the use of the substance in situ by impregnating raw material in metal salt solution immersion,drying,in-situ co-reduction treatment technology supported nickel-carbon material on the bimetal nanoparticles to produce nickel-based/biochar composite nano-catalyst,by changing the concentration of the metal salt solution,the heat treatment temperature and the type of biomass material and other experimental parameters to regulate the size,loadings of metal nanoparticles,and studies the morphology,structure and properties of nickel-based/biochar composite nano-catalyst.The main results are as follows:（1）High temperature oxygen-controlled carbonization preparing porous biochar to asparagus,radish,potato biomass material as the object of study,the heat treatment temperature and different drying processes for preparing biological microstructure carbon material,substance the phase behavior and the influence of pore size.The results showed that:a biochar material prepared under conditions of freeze-drying process to maintain a more complete structure,and can regulate the morphology and pore size of the porous carbon by a heat treatment temperature of the biological structure and biological properties of the optimum temperature of the carbon precursor itself relevant.（2）By impregnation and in situ co-reduction techniques supported metallic nickel nanoparticles on the biomass material,the effect of the metal salt solution concentration,the heat-treatment temperature and biomass material were discussed.The results showed that:a uniform composite nano-Ni-C catalyst（0.3-Ni-AG-800）after the optimization of experimental parameters of Ni nano-particles are distributed biological material,the carbon support（average particle size of 3.4 nm）;and has good electrocatalytic activity and stability at a current density of 10 mA·cm^-2 of,HER and OER overpotential of 171 mV and 319 mV,respectively,it’s HER for 10 hours without significant loss of activity after long-term stability test.（3）By impregnation and in situ co-reduction techniques supported nickel metal bis（NiFe,NiCo）nanoparticles,the effect of concentration ratio,heat-treatment temperature was discussed.The results showed that when a concentration ratio of 7:3,the heat-treatment temperature of 800℃,nickel-based bimetal/biochar（NiFe-C,NiCo-C）Complex Catalysts achieve the best performance for hydrogen evolution.（4）The parameter optimization experiments using Ni-C,NiFe-C and NiCo-C nanocomposite as a nickel-based oxide/carbon composite nano biological catalyst precursor,Discussion the effect of the oxide temperature for Ni/NiO-C,NiFeOx-C and NiCoOx-C complex catalysts.The results showed that when the oxide temperature is200℃,nickel-based oxide/biochar（Ni/NiO-C,NiFeOx-C and NiCoOx-C）composite catalysts achieve the best performance for hydrogen evolution.