The effect of promoting 15%Co/Al₂O₃ catalyst with potassium on CO₂ hydrogenation to longer-chain hydrocarbons was investigated. The catalysts used in this study were synthesized using an incipient wetness impregnation of the support with nitrate solutions. All catalysts were supported on γ-alumina and promoted with potassium (0 – 8%). The synthesized catalysts were characterized by XRD, BET, XPS, TPR and CO₂-TPD analyses. The catalysts were evaluated for CO₂ hydrogenation using a fixed-bed tube reactor. The CO₂ conversion was found to increase with both the reaction temperature and pressure. The TPR data revealed that potassium limited the reduction of the catalyst, decreased the selectivity to methane and increased the selectivity to C₂₊ hydrocarbons. The maximum C₂₊ yield of 10.2%, with CO₂ conversion of 42.3%, was obtained when 6 wt.% of potassium was added to the catalyst. It is believed that during the CO₂ hydrogenation process over the catalysts that were promoted with potassium, CO₂ is first converted to CO via reverse–water–gas–shift reaction, followed by subsequent hydrogenation of CO to hydrocarbons.

研究了用钾促进15％Co / Al ₂ O ₃催化剂对CO ₂加氢成长链烃的影响。本研究中使用的催化剂是通过用硝酸盐溶液对载体进行初期湿润浸渍而合成的。所有催化剂都负载在γ-氧化铝上，并用钾（0 – 8％）促进。通过XRD，BET，XPS，TPR和CO ₂ -TPD分析对合成的催化剂进行了表征。使用固定床管式反应器评估催化剂的CO ₂加氢。一氧化碳₂发现转化率随着反应温度和压力的增加而增加。TPR数据表明，钾限制了催化剂的还原，降低了对甲烷的选择性，并提高了对C ₂₊烃的选择性。当将6重量％的钾添加到催化剂中时，获得最大的C ₂₊收率10.2％，CO ₂转化率为42.3％。可以认为，在钾促进的催化剂上进行CO ₂加氢过程中，CO ₂首先通过逆水-气-煤气变换反应转化为CO，然后再将CO加氢为烃。