CO2加氢制备甲醇是实现“双碳”目标的重要途径,通过添加不同含量的Mg对CuZnAlY催化剂进行改性,并系统研究了其对CO2加氢制甲醇性能的影响。通过XRD、TPR、TPD和XPS等表征手段对催化剂结构特征进行了系统分析。结果表明,Mg的添加构筑了合适的碱性位点,增强了CO2吸附能力,提升了CO2转化率和甲醇选择性。其中CZAYM2.5复合催化剂时空产率最高,在T=250℃,P=3.0MPa,GHSV=4000mlmlcat−1h−1,反应气H2∶CO2=3∶1(摩尔比)条件下,CO2转化率、甲醇选择性和甲醇时空产率分别达到了18.95%、51.49%和0.1549ggcat−1h−1。在提高反应压力P=5.0MPa条件下进行了720h稳定性试验,结果表明:CO2转化率达到了22.00%,CH3OH选择性保持在63.00%左右,时空产率保持在0.2100ggcat−1h−1左右,催化剂表现出良好的稳定性能。

CO2 hydrogenation to methanol is an important way to achieve the goal of "double carbon". In this paper,CuZnAlY catalyst wasmodified by adding different contents of Mg,and its effect on the performance of CO2 hydrogenation to methanol was systematicallystudied. XRD,TPR,TPD and XPS were used to analyze the structure of the catalyst. The results showed that the addition of Mg built asuitable alkaline site,enhanced the CO2 adsorption capacity,improved the CO2 conversion and methanol selectivity. Among them,CZAYM2.5 composite catalyst has the highest space-time yield. Under the conditions of T=250 ℃,P=3.0 MPa,GHSV=4000 ml mlcat h,reaction gas H2:CO2=3:1 (molar ratio),the CO2 conversion,methanol selectivity and methanol space-time yield reached 18.95%,51.49% and 0.1549 g gcath,respectively. Meanwhile,stability tests were carried out for 720 h at improved pressure P=5.0 MPa. Theresults showed that:the CO2 conversion reached 22.00%,the selectivity of CH3OH was about 63.00%,and the methanol space-time yieldwas about 0.2100 g gcath. The catalyst showed good stability.