石墨烯负载Pt催化剂的催化氧化发光性能

Cataluminescence Performance on Catalysts of Graphene Supported Platinum

利用溶胶固定化工艺合成了石墨烯负载Pt纳米颗粒的Pt/石墨烯催化剂.研究了分散在石墨烯上的Pt颗粒尺寸和负载量对CO催化发光性能的影响规律,探查了催化剂的某些分析特性及对其它气相体系的催化氧化性能.结果表明,Pt纳米颗粒可以很好地分散在石墨烯表面,并有较快的催化反应速率,Pt颗粒越小催化发光强度越大.当不同Pt负载量(0.4%-1.6%(w,质量分数))的催化剂作用于40%(φ,体积分数)以下浓度的CO/空气体系时,产生的催化发光强度均与CO浓度成正比,其中以负载量0.8%最优;但随CO浓度继续增加,低Pt负载量(0.4%,0.8%)催化剂的发光强度下降,而高Pt负载量(1.2%,1.6%)催化剂的发光强度继续上升,且Pt负载量越高,催化氧化发光能力越强.该催化剂在一定条件下,不但对CO氧化有较好的催化发光性能,还对乙醚、无水甲醇和甲苯有不同程度的催化氧化发光活性;但二氧化碳、甲醛、戊二醛、丙酮、乙酸乙酯、三氯甲烷、水蒸气均无响应信号.

Platinum nanoparticles supported by graphene were prepared by the colloid deposition process. The effects of particle size and loading amount of platinum particles on the cataluminescence （CTL） properties of CO have been investigated. The CTL properties and some analysis characteristics of the catalyst on other gas phase systems were explored. The results show that the Pt nanoparticles are well distributed on graphene and a faster catalytic reaction rate is apparent. The smaller particles lead to a higher CTL intensity. When the volume concentration of CO in air is below 40% （φ, volume fraction） the CTL intensity is proportional to the concentration of CO for all the catalysts （0.4%-1.6% （w, mass fraction） Pt）. Among them, the catalyst containing 0.8% Pt was found to be the best. However, by increasing the CO concentration the CTL intensity of the catalysts with a low Pt loading （0.4%, 0.8%） decreased while the highly loaded （1.2%, 1.6%） catalysts continued to increase their intensity. Moreover, a higher Pt loading led to a higher CTL intensity. Under certain conditions the catalyst shows good CTL performance for CO oxidation, and ether, methanol as well as toluene show different degrees of response. No response was obtained for carbon dioxide, formaldehyde, glutaraldehyde, acetone, ethyl acetate, chloroform, and water vapor.