Effects of Promoter’s Composition on the Physicochemical Properties of Cu/ZnO/Al<sub>2</sub>O<sub>3</sub>-ZrO<sub>2</sub> Catalyst
Nur Insyirah Zulkifli,
Noor Asmawati Mohd Zabidi,
Zulkifli Merican Aljunid Merican,
Sara Faiz Hanna Tasfy
Affiliations
Nur Insyirah Zulkifli
Center of Contaminant Control and Utilization (CenCoU), Institute of Contaminant Management for Oil and Gas, Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, Seri Iskandar 32610, Perak, Malaysia
Noor Asmawati Mohd Zabidi
Center of Contaminant Control and Utilization (CenCoU), Institute of Contaminant Management for Oil and Gas, Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, Seri Iskandar 32610, Perak, Malaysia
Zulkifli Merican Aljunid Merican
Center of Contaminant Control and Utilization (CenCoU), Institute of Contaminant Management for Oil and Gas, Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, Seri Iskandar 32610, Perak, Malaysia
Sara Faiz Hanna Tasfy
Department of Chemical and Petroleum Engineering, American University of Ras Al Khaimah, Ras Al Khaimah 10021, United Arab Emirates
Cu/ZnO catalysts were synthesized via an impregnation method on an Al2O3-ZrO2 support and modified by the addition of manganese and niobium as promoters. The effect of the selected promoters on the physicochemical properties and performance toward the hydrogenation of CO2 to methanol are presented in this paper. The Mn and Nb promoters improved the reducibility of the catalyst as evidenced by the shifting of the H2-TPR peaks from 315 °C for the un-promoted catalyst to 284 °C for the Mn- and Nb-promoted catalyst. The catalytic performance in a CO2 hydrogenation reaction was evaluated in a fixed-bed reactor system at 22.5 bar and 250 °C for 5 h. Amongst the catalysts investigated, the catalyst with equal ratio of Mn and Nb promoters exhibited the smallest particle size of 6.7 nm and highest amount of medium-strength basic sites (87 µmol/g), which resulted in the highest CO2 conversion (15.9%) and methanol selectivity (68.8%).