Insights into the methanol synthesis mechanism via CO2 hydrogenation over Cu-ZnO-ZrO2 catalysts: Effects of surfactant/Cu-Zn-Zr molar ratio

Author(s)

Marcos, Francielle C. F. ^[1] ; Lin, Lili ^[2] ; Betancourt, Luis E. ^[2] ; Senanayake, Sanjaya D. ^[2] ; Rodriguez, Jose A. ^[2] ; Assaf, Jose M. ^[3] ; Giudici, Reinaldo ^[1] ; Assaf, Elisabete M. ^[4]

Affiliation

^[1] Univ Sao Paulo, Escola Politecn, Av Prof Luciano Gualberto 3, BR-05508010 Sao Paulo, SP - Brazil

^[2] Brookhaven Natl Lab, Chem Div, Upton, NY 11973 - USA

^[3] Univ Fed Sao Carlos, Km 235, BR-13565905 Sao Carlos, SP - Brazil

^[4] Univ Sao Paulo, Sao Carlos Inst Chem, Av Trabalhador Sao Carlense 400, BR-13560970 Sao Carlos, SP - Brazil

• Document type: Journal article
• Source: JOURNAL OF CO2 UTILIZATION; v. 41, OCT 2020.
• Web of Science Citations: 2

Abstract

In this study, we evaluated aspects of the CO2 hydrogenation mechanism, correlating structure-activity relationships of Cu-ZnO-ZrO2 catalysts prepared by one-pot surfactant-assisted co-precipitation with different surfactant ratios. Identifying the CO2 hydrogenation pathway intermediates is key to controlling the reaction selectivity. Experimental evidence shows that the CO2 is dissociating into CO{*} and O{*} onto the surface of the CuZnO-ZrO2 catalyst. The adsorption and dissociation of CO2 were evidenced by a combination of in situ ambient pressure X-ray Photoelectron Spectroscopy (AP-XPS) and Fourier Transform Infrared Spectroscopy (FTIR) with a transmission cell. AP-XPS showed that the catalysts are composed of a Cu2+, Zr3+, and Zr4+ mixture and two kinds of Zn2+ species. After the H-2 reduction process, only Cu2+ was reduced to Cu-0. The Zn and Zr species were oxidized by the dissociated O{*} species. In situ transmission FTIR showed that CO was adsorbed onto the Cu+/0 sites. The catalyst with the higher surfactant molar ratio exhibited the highest CO2 conversion close to the equilibrium conversion, as well as a good methanol formation rate. (AU)

• FAPESP's process: 17/08293-8 - Project 14: direct synthesis of methanol from CO2
• Grantee: Francielle Candian Firmino Marcos
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 14/50279-4 - Brasil Research Centre for Gas Innovation
• Grantee: Julio Romano Meneghini
• Support Opportunities: Research Grants - Applied Research Centers Program
• FAPESP's process: 18/05799-0 - A surface science investigation of methanol synthesis on Cu-Ga/ZrO2 catalysts
• Grantee: Francielle Candian Firmino Marcos
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor