CO₂ hydrogenation to C₅₊ isoalkanes on ZnZr/HZSM-5 composite catalyst

Zinc-zirconium oxide (ZnZr) was effectively coupled with HZSM-5 zeolite in this report. The effects of SiO₂/Al₂O₃ ratio of HZSM-5 zeolite and Zn/Zr ratio on the performance of CO₂ hydrogenation to C₅₊ isoalkanes over the composite catalyst were investigated, respectively. The results show that ZnZr-4/HZSM-5 prepared by SiO₂/Al₂O₃ = 130 and Zn/Zr = 1∶5 manifests the optimal performance of CO₂ hydrogenation to C₅₊ isoalkanes, with CO₂ conversion of 17% and CO selectivity of 25%, as well as the selectivity of C₅₊ hydrocarbons and isoalkanes in C₅₊ hydrocarbons up to 60% and 89%. Moreover, ZnZr/HZSM-5 composite catalyst shows excellent stability with time on stream for 120 h without losing activity. A suitable coupling between ZnZr and HZSM-5 zeolite is critical for highly selective synthesis of C₅₊ isoalkanes by CO₂ hydrogenation.