沉淀温度对Pd-Cu/凹凸棒土结构及其CO常温催化氧化性能的影响

以凹凸棒土(APT)为载体,NH3·H2O为沉淀剂,采用沉积-沉淀法制备Pd-Cu/APT催化剂。在连续流动微反装置上,考察不同沉淀温度对Pd-Cu/APT催化剂CO常温催化氧化性能的影响。利用N2物理吸附-脱附、XRD、FT-IR和H2-TPR等对Pd-Cu/APT催化剂进行表征。结果表明,不同沉淀温度制备的催化剂均含有Cu2Cl(OH)3和CuO两种形式的Cu物种,但与沉淀温度25℃和90℃制备的催化剂相比,沉淀温度70℃制备的催化剂具有更多的活性Cu2Cl(OH)3物种,这有利于Pd2+物种的再生,显著提高其CO常温催化氧化活性。

Effect of precipitation temperature on structure and catalytic performance of Pd-Cu/attapulgite clay catalyst for room-temperature CO oxidation

Pd-Cu/APT catalysts were prepared by deposition-precipitation method with attapulgite clay (APT) as supporter and NH₃·H₂O as precipitant.The effect of precipitation temperature on the catalytic performance of Pd-Cu/APT catalyst for room-temperature CO oxidation was investigated in a fixed-bed continuous flow reactor.The Pd-Cu/APT catalysts were characterized by N₂-physisorption,XRD,FT-IR and H₂-TPR.The results show that Pd-Cu/APT catalysts prepared at different precipitation temperatures possess the same Cu₂Cl(OH)₃ and CuO species.However,compared with Pd-Cu/APT catalysts prepared at precipitation temperatures of 25 ℃ and 90 ℃,the catalyst prepared at precipitation temperature of 70 ℃ has more active Cu₂Cl(OH)₃ species,which is beneficial to the regeneration of Pd²⁺ species and could significantly improve its catalytic activity of room-temperature CO oxidation.