制备条件对CuFe双金属催化剂混合醇合成的影响

Effect of preparation conditions of CuFe bimetallic catalyst on mixed alcohol synthesis

采用液相还原法制备了用于混合醇合成的CuFe双金属催化剂,结合XRD、低温Ar吸附-脱附和H_(2)-TPR等表征方法,研究了液相还原过程中催化剂制备温度、分散剂种类及用量、pH等制备条件对催化剂反应活性及C_(2)^(+)混合醇选择性的影响;分析了催化剂结构及反应性能间的构-效关系,并优选了制备条件。实验结果表明,较低的制备温度、较高的分散剂(乙二醇)用量、pH中性有助于活性金属组分的分散,促进双金属协同效应,提高催化剂反应活性及C_(2)^(+)混合醇选择性;综合考虑CO转化率、总醇选择性及C_(2)^(+)醇选择性,液相还原法制备CuFe双金属催化剂较适宜的条件为:以300 mL乙二醇为分散剂、冰水浴、pH=7.0。

CuFe bimetallic catalysts for mixed alcohol synthesis were prepared by liquid phase reduction method.By characterization methods of XRD,low-temperature Ar adsorption-desorption and H_(2)-TPR,the effects of the preparation conditions containing preparation temperature,dispersing agent kind and amount,pH,etc.on reaction activity of the catalyst and selectivity of C_(2)^(+)mixed alcohol were studied.The structure-function relationship between catalyst structure and reaction performance were investigated,and the preparation conditions were optimized.The experimental results show that a lower preparation temperature,higher dispersant(glycol)amount and neutral pH can be conducive to the dispersion of active metals,the promotion of bimetal synergistic effect,and the improvement of reaction activity of catalyst and selectivity of C_(2)^(+)mixed alcohol.Considering CO conversion,selectivity of total alcohols and selectivity of C_(2)^(+)mixed alcohol,the optimum conditions for CuFe bimetallic catalyst preparation by liquid phase reduction method are as follows:300 mL ethylene glycol as dispersant,ice water bath and pH 7.0.