Preparation Of Porous Titania Thin Film And Study On Its Properties Of Nickel-based Methanation Catalyst

The channel of microreactor is small,the traditional catalyst in which easy agglomeration and clogging.Therefore,it is an effective method to solve the problem by supporting the catalyst in the form of a film and carrying out a catalytic reaction.In order to study the catalytic performance of the film catalyst,the porous titanium dioxide film prepared by the preparation method was supported on the surface of the aluminum wire substrate,and the active component Ni was loaded by impregnation to carry out the more environmentally friendly CO methanation reaction.The effects of preparation conditions such as amount of template,aging time and heat treatment temperature on the porous titanium dioxide film were studied.The activity and stability of Ni-based methanation catalyst were studied.The main findings are as follows:(1)The porous titanium dioxide thin film was prepared on the surface of the pretreated aluminum wire substrate by using sol-gel method with evaporation-induced self-assembly and solvent-impregnated dip-coating technique and block copolymer F127 was used as template.The results show that when the amount of F127 is 1.0g,the aging time is 24 h and the heat treatment temperature is 400℃(in the mixed solution of 15 mL ethanol,1mL deionized water,1mL hydrochloric acid,5mL tetrabutyl titanate and 0.2mL acetylacetone),the porous titanium dioxide film has a uniform porous structure and the best structural properties.The specific surface area and pore volume can reach 127 m2 · g-1 and 0.2139 cm3 · g-1,respectively.(2)The preparation of porous titanium dioxide film by using block copolymer F127 and P123 as the mixed template can optimize the pore structure of the film,increase the specific surface area and pore volume.Among them,when the amount of F127 and P123 is 1.0g and the mass ratio is 3: 1,the prepared titanium dioxide film has higher specific surface area and pore volume,which can reach 154m2 · g-1 and 0.3031cm3 · g-1,respectively.(3)The titanium dioxide film prepared by this method exhibits anatase phase at the heat treatment temperature of 300 ℃,400 ℃ and 500 ℃,and the type of template does not affect its crystal phase.In this sol-gel system,the decomposition temperature of template is about 312 ℃.(4)The porous titanium dioxide film prepared with the optimum mixing ratio of the template is used as the catalyst support,and the active component Ni is supported by the impregnation method to form the Ni / TiO2 film methanation catalyst.The catalytic activity and stability of the catalyst were evaluated under the conditions of WHSV of 3000 mL · g-1 · h-1.The results show that Ni / TiO2 film methanation catalyst is successfully supported on the surface of porous titanium dioxide film,and the active component is mainly supported on the surface of the porous film in the form of NiO before reduction.It can be found that Ni O can be produced by H2-TPR.The conversion of CO was higher than 99% and the selectivity of CH4 was close to 80% at the reaction temperature exceeding 400 ℃.Besides,the film catalyst also has good catalytic stability in the long-term stability evaluation for up to 60 h.