Preparation Of Platinum Nanoparticles Composite And Their Properties Of Formaldehyde Oxidation Catalyzed In Normal Temperature

With the improvement of human science and living standards,the requirement for the quality of the air environment has been continuously improved.Researchers have deeper understanding of the system of formaldehyde hazards.The removal or the reduction of indoor formaldehyde concentration has become an urgent problem to be solved.Platinum nanoparticles composites have great advantages of high catalytic efficiency,good stability,no secondary pollution,and they have attracted extensive attention from researchers.In this paper,noble metal platinum nanoparticles were loaded on the surface of a metallic titanium mesh and a cordierite honeycomb ceramic carrier to prepare an inorganic nanoparticle composite capable of catalyzing the oxidation of formaldehyde at room temperature.The platinum nanoparticle with a particle size distribution of 2-10 nm is prepared by a one-step reduction method.The influence of parameters such as the type and concentration of the reducing agent,the concentration of the protective agent is investigated.Results show that the obtained small-sized platinum nanoparticles can be prepared using ethanol as a reducing agent.Reducing the proportion of ethanol in the solution,the particle size of nano-particles increases continuously,and the reduction rate is an important factor in the preparation of small-sized nano-particles.Increasing the concentration of the protective agent will reduce the size of the nanoparticles and the size distribution will remain narrow.In order to solve the problem that the catalyst module is not easy to be shaped,a Pt/Ti O2 composite is prepared by the titanium metal mesh and noble metal platinum nanoparticles.For further improving the adsorption effect of formaldehyde on the composites,Pt/Ti O2/CHC is prepared by the composite of platinum nano-particles,nano-titanium dioxide and cordierite honeycomb ceramics.SEM and EDX characterization showed that the nanoparticles are supported on the titanium mesh carrier surface;XRD results indicate that the Pt nanoparticles are uniformly dispersed.The formaldehyde decomposition test results show that Pt/Ti O2 composites prepared by colloidal loading of Pt nanoparticles can catalyze the highest decomposition efficiency of formaldehyde at 15.6%,and the catalytic decomposition efficiency of Pt/Ti O2/CHC composites can reach 22%.The catalyst loaded with small particle size nanoparticles has higher catalytic efficiency for the higher catalytic activity.With the increase of Na+ loading,the decomposition efficiency of formaldehyde increases.When the loading of Na+ reaches 3%,the catalytic efficiency of the catalyst is the highest,and further increasing the loading of Na+ can no longer increase the catalytic efficiency.In addition,as the calcination temperature of the substrate increases,the phase of Ti O2 film transforms from the anatase to the rutile,resulting in a decrease in the catalytic performance of formaldehyde decomposition;and the calcination temperature of the composite will also produce formaldehyde decomposition properties by changing the valence state of the surface Pt element.