前驱体制备方法对Cu-Fe基浆状催化剂制取低碳醇性能的影响

Effect of precursor preparation methods on performance of Cu-Fe-based slurry catalyst for synthesis of higher alcohols

采用共沉法(CP)、溶胶-凝胶法(SG)和水热法(HT)三种方法分别制备Cu-Fe基催化剂前驱体,利用完全液相法对制得的前驱体进行热处理,获得Cu-Fe基浆状催化剂,并在浆态床反应器上进行了一氧化碳加氢制取低碳醇的性能研究;利用BET、XRD、XPS、H2-TPR、NH3-TPD-MS等方法对催化剂结构和双金属协同效应进行了表征分析。结果表明,不同Cu-Fe基催化剂前驱体经热处理后表现出不同的金属分布情况、化学特性、物相组成和双金属间的协同作用,尤其是稳定的Cu0粒径、较好的Cu-Fe协同作用、较大的比表面积和催化剂表面上的弱酸位点是合成气制低碳醇的关键;共沉淀法制备的前驱体催化剂表现出较优的活性,在低温220℃、低压3 MPa下,总醇选择性达到46.87%,低碳醇的质量分数为83.44%。

Different precursors of catalyst prepared by CP,SG and HT were heat-treated by complete-liquid phase process to obtain Cu-Fe-based slurry catalysts,and the performances of the prepared catalysts in CO hydrogenation to produce higher alcohols were examined in a slurry bed reactor.The catalyst structure and the bimetallic synergistic effect were characterized by BET,XRD,XPS,H2-TPR and NH3-TPD-MS.The results showed that different precursors of Cu-Fe-based catalysts exhibited different metal distribution,chemical characteristics,phase composition and bimetallic synergistic effect after heat treatment.In particular,stable Cu°particle size,synergistic effect of Cu-Fe,large specific surface area and weak acid sites on catalyst surface are the keys to the synthesis of higher alcohols from syngas.The catalyst precursor prepared by co-precipitation showed superior activity.At 220℃and3 MPa,the total alcohol selectivity reached 46.87%,and the mass fraction of higher alcohols in the total alcohol was 83.44%.