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在乙醇水体系中利用硼氢化物液相还原法合成纳米铁颗粒,通过化学沉淀法将钯金粒子负载于纳米铁表面,得到纳米钯金铁(Pd-Au@Fe)三金属催化剂复合材料,采用TEM,EDS和XPS对其进行表征.结果表明,与纳米单金属Fe0及双金属Pd@Fe相比,三金属催化剂对三氯乙烯(TCE)具有更高的降解能力.保持催化剂加量1.4g/L,Pd/Fe为0.35%(ω),Au/Fe为1.0%(ω)时,其降解15mg/L TCE的速度最快,5min时去除率为88.21%,表观速率常数为0.311min-1,是相同Pd含量下Pd@Fe双金属催化剂的3.6倍.随降解反应持续,Pd-Au@Fe的乙烯乙烷生成率及乙烯加氢转换乙烷速率均远高于双金属Pd@Fe.
The nano-iron particles were synthesized by the liquid-phase reduction method of borohydride in ethanol water system and the palladium particles were supported on the surface of the nano-iron by the chemical precipitation method to obtain the Pd-Au @ Fe trimetallic catalyst composite, The results were characterized by TEM, EDS and XPS.The results showed that the trimetallic catalysts have higher degradation ability to TCE than nano-Fe0 and bimetallic Pd @ Fe.The amount of catalyst 1.4 g / L, Pd / Fe 0.35% and Au / Fe 1.0%, the removal rate of 15mg / L TCE was the fastest, the removal rate was 88.21% at 5min and the apparent rate constant was 0.311 min-1, which is 3.6 times that of Pd @ Fe bimetallic catalyst with the same Pd content.With the continuous degradation reaction, the yield of ethylene-ethane and the ethylene-to-ethylene conversion rate of Pd-Au @ Fe are much higher than that of bimetallic Pd @Fe.