Regulating Growth Of Pt Catalyst On Polystyrene Microspheres Surface And Its Properties

Due to the extremely radioactivity,the effluent liquid and exhaust gas containing quantities of tritium discharged by nuclear equipment has a seriously harmful effect on ecological environment.With the development of nuclear energy industry,the treatment technology of containing tritium wastewater and waste gas is particularly important,Tritium has an extremely important strategic significance in the military and other fields.In this paper,two-dimensional controlled growth of platinum surface morphology of platinum hydrophobic catalyst surface was successfully achieved by controlling the experimental conditions.Three polystyrene microspheres with different surface properties were prepared by suspension polymerization and emulsion polymerization respectively,they were PS,PS-and W,they were Characterized by XG-CAM,TEM,SEM,FTIR,CO-FTIR,TG.On the basis of the results obtained with surface property characterizations,support PS?PS-prepared by suspension polymerization exhibited obviously higher hydrophobic nature then support W prepared by emulsion polymerization.Support W exhibited largest specific surface area and support PS showed stronger capacity of the adsorption of CO.According to the the experimental goal,Pt precursor solution was mixed with support and the conditions were changed to prepared hydrophobic platinum catalyst.The systematically characterized results showed that catalyst prapared using PS as support exhbiting super-hydrophobicity possessed an obviously higher hydrophobic nature than other support.With the m(PS)/m(Pt)ratio increased,the contact angle decreased,the amounts of zero valence Pt on the catalyst surface increased firstly and then decreased,and the maximum value appeared at m(PS)/m(Pt)=30:1.When the ratio came to 40,platinum nanoparticles were distributed evenly and monolayer on the support surface,and no clustering was observed.When PVP was added,the loading point for Pt reduced,and the agglomeration of platinum nanoparticles appeared accompanied by the increase of zero valence Pt.The superficial Pt exhbited overlapped,arc-shaped and sphericity morphologies on catalyst surface when the concentration of precursor solution(c([PtCl6]2-))were 0.118 mg/mL,0.091 mg/mL and 0.074 mg/mL respectively with controled m(PS)/m(Pt)ratio of 30.W support has the ability of controlling the growth and morphologies of Pt nanoparticle.The superficial Pt nano particle turn into rodlike and(111)crystal face was exposed when the ratio of m(PVP)/m(Pt)remained at 5 and m(W)/m(Pt)was 2.While the ratio of m(W)/m(Pt)turn to 10,the well dispersed monolayer arc-shaped Pt nanoparticle on catalyst surface were found.When PS-was used as support,the load point for Pt reduced,the agglomeration of platinum nanoparticles appeared.This implied that support has great influence on the Pt dispersion and morphologies.The catalytic performance of the catalyst in this paper is simulated by H,D isotope exchange on the surface of the catalyst.On the basis of experient results,CTAB-PS-Pt-20:1 catalyst possessed the best isotopic exchange catalytic efficiency.The exchange efficiency reached to 81.4%and 84.27%respectively at 50? and 60? with hydrogen flow of 0.64 L/min.The addition of CTAB had positive effect on catalytic performance.