Enhanced catalytic performance of Zr modified CuO/ZnO/Al2O3 catalyst for methanol and DME synthesis via CO2 hydrogenation. Issue 36 (February 2020)

• Record Type: Journal Article
• Authors: Ren, Shoujie; Fan, Xiao; Shang, Zeyu; Shoemaker, Weston R.; Ma, Lu; Wu, Tianpin; Li, Shiguang; Klinghoffer, Naomi B.; Yu, Miao; Liang, Xinhua
• Is Part Of: Journal of CO₂ utilization. Issue 36(2020)
• Page Start: 82
• Page End: 95
• Publication Date: 2020-02
• Subjects: CO2hydrogenation -- Methanol -- Dimethyl ether -- CuO/ZnO/ZrO2/Al2O3 (CZZA) -- Stability; Carbon dioxide -- Periodicals; Carbon dioxide -- Environmental aspects -- Periodicals; Carbon dioxide mitigation -- Periodicals; Carbon dioxide; Carbon dioxide -- Environmental aspects; Carbon dioxide mitigation; Periodicals; 628.53205
• DOI: 10.1016/j.jcou.2019.11.013
• Languages: English
• ISSNs: 2212-9820

Abstract

Graphical abstract: Zr modified CuO/ZnO/Al2 O3 has superior stability for methanol synthesis and significantly improved catalyst stability for DME synthesis, compared to CuO/ZnO/Al2 O3 catalyst. Highlights: Zr modification of CZA catalyst enhanced activity for methanol and DME synthesis. CZZA catalyst showed a superior stability for methanol synthesis. Zr modification greatly improved bifunctional catalyst stability for DME synthesis. Structure changes and coking of HZSM-5 were responsible for catalyst deactivation. Abstract: Zirconium (Zr) modified CuO/ZnO/Al2 O3 (CZA) catalysts with different aluminum (Al) and Zr contents were synthesized by the co-precipitation method. The synthesized CuO/ZnO/ZrO2 /Al2 O3 (CZZA) catalysts were comprehensively characterized and studied for methanol synthesis via CO2 hydrogenation. The CZZA catalyst showed the highest methanol yield of 12.4 % at 220 °C and 2.76 MPa with an optimized catalyst composition of Cu/Zn/Zr/Al (atomic ratio) at 4:2:1:0.5. The CZZA catalyst showed better activity than that of the CZA catalyst and a superior stability for methanol synthesis. There was no decrease in the BET surface area and very little coke formation for the spent CZZA catalyst, after 300 h of methanol synthesis. Bifunctional catalysts, composed of CZZA and HZSM-5, were investigated for dimethyl ether (DME) synthesis directly from CO2 hydrogenation, and a maximum DME yield of 18.3 % was obtained at a reaction temperature of 240 °C and a pressure of 2.76 MPa. The stability of the bifunctional CZZA and HZSM-5 catalyst during the DME synthesis also significantly improved, as compared to that of the CZA and HZSM-5. A significant decrease in the BET surface area and an increase in coking on the spent CZZA catalyst were observed after 100 h of DME synthesis, indicating a detrimental effect on CZZA stability when a HZSM-5 catalyst was present. The changes in structural properties (e.g., BET surface area and crystallinity) and coking for HZSM-5 could be responsible for the deactivation of the bifunctional catalyst.