喷雾干燥法制备碳载铂钴镍合金催化剂及其甲醇催化氧化性能研究

Preparation of PtCoNi Alloy Nanoparticles Loaded on Carbon Black by Spray Drying for Catalytic Oxidation of Methanol

以氯铂酸、氯化镍和硝酸钴为原料,XC-72炭黑为载体,通过雾化干燥法结合煅烧还原制备碳载铂基(PtCoNi)分散性好的多元合金纳米粒子催化剂。重点研究表面经过改性的炭黑对合金纳米粒子形成和分散的影响规律,研究碳载PtCoNi(原子比为1:1:1)合金纳米粒子的甲醇催化氧化活性、抗CO中毒能力和耐久性,以及不同原子比对催化氧化甲醇活性和抗CO中毒能力的影响规律。结果表明,采用表面改性后的炭黑作为载体,制备的碳载铂基(PtCoNi)催化剂为合金纳米粒子,且纳米粒子在炭黑表面分散均匀,粒径分布在1~4 nm,平均粒径为2.3 nm;与商用的Pt/C催化剂相比,PtCoNi/C(原子比为1:1:1)催化剂具有更高的甲醇催化氧化活性、耐久性和抗CO中毒性;不同原子比铂基多元催化剂在催化氧化甲醇活性上的顺序为:PtCoNi/C>Pt3CoNi/C>Pt5CoNi/C,抗CO中毒性顺序为:PtCoNi/C>Pt3CoNi/C>Pt5CoNi/C。

The chloroplatinic acid,nickel chloride and cobalt nitrate,as raw materials,were used to synthesize PtCoNi alloy nanoparti cles with well dispersion loaded on XC-72 carbon black by spray drying method combined with calcination reduction.The influence of the surface of the carbon black on the formation and dispersion of alloy nanoparticles was studied,and the effects of PtCoNi with the same atomic ratio and PtCoNi with different atomic ratios on methanol catalytic oxidation activity and CO poisoning resistance and durability were investigated.The results show that PtCoNi catalyst loaded on surface modified carbon black is alloy nanoparticles,and the nanoparticles are dispersed evenly on the surface of carbon black with particle size distribution of 1~4 nm and average particle size of 2.3 nm.Compared with commercial Pt/C catalysts,PtCoNi/C with the same atomic ratio has higher catalytic methanol oxidation activity,durability and CO poisoning resistance.The order of activity of PtCoNi catalysts with different atomic ratios in catalytic methanol oxidation reaction is:PtCoNi/C>Pt3CoNi/C>Pt5CoNi/C,and the sequence of CO poisoning resistance is PtCoNi/C>Pt3CoNi/C>Pt5CoNi/C.