随车制氢甲醇裂解铜水泥催化剂的研究

Copper-Cement Catalyst for Onboard Hydrogen Generation by Methanol Decomposition

分别以H2O,H3BO3,C6H8O7,NH3.H2O为溶剂,采用离子交换法制备了铜水泥催化剂,并在固定床上考察了催化剂催化甲醇裂解的性能。实验结果表明,以H2O代替NH3.H2O制得的铜水泥催化剂性能优越,实现了催化剂制备的环保高效。与商用的CuZnAl甲醇裂解催化剂相比,铜水泥催化剂具有较高催化活性和选择性,在常压、300℃、重时空速3.39h-1的条件下,铜水泥催化剂的比活性(甲醇转化率与铜负载量的比值)和CO+H2的选择性分别为2.44和95.9%,CuZnAl催化剂分别为0.64和89.2%;铜水泥催化剂的抗压强度大于45N,而CuZnAl催化剂的抗压强度为20N。铜水泥催化剂具有机械强度高、活性高、CO+H2选择性高的特点,基本满足了随车制氢的要求。XRD,SEM,DTG-DTA,FTIR,H2-TPR表征结果显示,铜水泥催化剂制备过程中形成的CaCO3具有稳定铜物种的作用,有助于保持催化剂的高温活性。

Cu-cement catalysts were prepared by an ion exchange method with H2O, H3 BO3, C6H8O7 or NH3·H2O as the solvent and evaluated through methanol decomposition in a fixed bed reactor. The Cu-cement catalyst prepared with H20 instead of NH3·H2O exhibited excellent catalytic performance. It was found that both activities and selectivities of the catalysts in the methanol decomposition were higher than those of the commercial CuZnAl catalyst. The specific activities （ methanol conversion/copper loading） of the CuZnA1 and the Cu-cement were 0.64 and 2.44, and their selectivities to CO ＋ H2 reached 89.2% and 95.9% respectively, under 0. 1 MPa, 300℃ and WHSV 3.39 h^-1. The crush strengthes of the Cu-cement catalysts and the CuZnAl catalyst were more than 45 N and 20 N, respectively. So the performances of the Cu-cement catalysts could meet the requirements for onboard hydrogen generation. The Cu-cement catalysts were characterized by means of XRD, SEM, DTG-DTA, FTIR and H2-TPR. The results showed that CaCO3 formed in the catalyst preparation process could stabilize the copper species in the catalysts, which could maintain the catalyst activity at high reaction temperature.