在许多催化应用中双金属的PdAu催化剂性能优于单金属催化剂.科研人员对具有可控纳米结构和高活性的PdAu催化剂进行了广泛的研究,但该催化剂的制备需要多步且通常步骤复杂.本文仅通过浸渍和焙烧制得了Au掺杂的负载型Pd催化剂,所得PdAu/C催化剂用于室温水相三氯乙烯加氢脱氯反应.当Pd和Au负载量分别为1.0 wt%和1.1 wt%时,在经过干燥、空气处理和H2还原的过程后，所制得的PdAu/C催化剂活性最高,初始转化频率(TOF)为34.0×10–2 molTCEmolPd–1 s–1,是单金属1.0 wt%Pd/C催化剂TOF (2.2×10–2 molTCEmolPd–1 s–1)的15倍以上. X射线吸收光谱结果表明,金的加入避免了400oC焙烧时Pd的氧化.本文还提出了可能的催化剂纳米结构演变路径,以解释所观察到的催化现象.
Bimetallic palladium‐gold (PdAu) catalysts have better catalytic performance than monometallic catalysts for many applications. PdAu catalysts with controlled nanostructures and enhanced activi‐ties have been extensively studied but their syntheses require multiple and occasionally complicat‐ed steps. In this work, we demonstrated that supported PdAu catalysts could be simply prepared by doping a supported Pd catalyst with gold through wet impregnation and calcination. Resulting PdAu‐on‐carbon (PdAu/C) catalysts were tested for the room‐temperature, aqueous‐phase hydro‐dechlorination of trichloroethene. The most active PdAu/C catalyst (Pd 1.0 wt%, Au 1.1 wt%, dried/air/H2 process) had an initial turnover frequency (TOF) of 34.0 × 10–2 molTCE molPd–1 s–1, which was>15 times higher than monometallic Pd/C (Pd 1.0 wt%, initial TOF of 2.2 × 10–2 molTCE molPd–1 s–1). Through X‐ray absorption spectroscopy, the gold kept Pd from oxidizing under calcina‐tion at 400 °C. Probable nanostructure evolution pathways are proposed to explain the observed catalysis.
参考文献
| [1] | Maroun F;Ozanam F;Magnussen OM;Behm RJ.The role of atomic ensembles in the reactivity of bimetallicelectrocatalysts[J].Science,20015536(5536):1811-1814. |
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