Selective CH4 reform to methanol through partial oxidation over Bi2O3 at room temperature and pressure

Author(s)

de Oliveira, Jessica A. ; da Cruz, Jean C. ; Nascimento, Otaciro R. ; Ribeiro, Caue

• Document type: Journal article
• Source: APPLIED CATALYSIS B-ENVIRONMENTAL; v. 318, p. 10-pg., 2022-08-20.

Abstract

Herein, we propose that an efficient CH4 partial photooxidation to methanol depends on appropriate band edge positions in photocatalysts. We demonstrated our hypothesis using Bi2O3 since this semiconductor have a valence band favorable to produce .OH and a conduction band not advantageous to O-2.- which is crucial to keep O-2 available for .CH3 capture and CH3OH formation. A notably and selective partial photooxidation of methane to methanol was observed under visible light at room temperature and pressure. As a result, the productivity of methanol over Bi2O3 can reach approximately 3771 mu mol g(-1) h(-1) with c.a. 65% selectivity avoiding over -oxidation to CO2. Isotope labeling experiment ((CH4)-C-13) confirmed that methane acts as the carbon source of methanol and ESR measurements proved the .CH3 and .OH generation. Besides, Bi2O3 exhibited good stability after 5 cycles maintaining a high and selective methanol production. These results provide insight into critical photocatalyst properties for the partial photooxidation of methane to methanol. (AU)

• FAPESP's process: 18/01258-5 - Novel chemical catalytic and photocatalytic processes for the direct conversion of methane and CO2 to products
• Grantee: José Maria Correa Bueno
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 19/21496-0 - Photoelectrochemical system design for CO2 and CH4 conversion to valuable products
• Grantee: Jéssica Ariane de Oliveira
• Support Opportunities: Scholarships in Brazil - Post-Doctoral