Role of Cu0-TiO2 interaction in catalyst stability in CO2 photoreduction process. Issue 2 (April 2022)

• Record Type: Journal Article
• Authors: Torres, Juliana A.; da Cruz, Jean C.; Nogueira, André E.; da Silva, Gelson T.S.T.; de Oliveira, Jéssica A.; Ribeiro, Caue
• Is Part Of: Journal of environmental chemical engineering. Volume 10:Issue 2(2022)
• Publication Date: 2022-04
• Subjects: Photocatalysis -- Copper -- Selectivity -- Heterostructure -- Stability; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2022.107291
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: The application of copper-based semiconductors for CO2 photoreduction has been limited by the poor stability of these catalysts in aqueous solutions due to parallel oxidation reactions. Thus, here we discussed the role of the Cu 0 -TiO2 interaction in catalyst stability, where the semiconductor acts as a charge separator and support for Cu 0 . Cu 0 nanoparticles were deposited on the surface of TiO2 by reducing copper nitrate using a sodium borohydride solution. The metallic copper presents a higher selectivity in CO production (82.32%), while pure TiO2 presents a selectivity for CH4 (62.44%). However, with the heterostructure formation, the photocatalysts activity increases and the selectivity changes with copper amount variation over TiO2 . In addition to the obtained C1 products (CH4, CO, and CH3 OH), products containing two or more carbons (C2+) were also generated, such as acetic acid (C2 H4 O2 ), acetone (C3 H6 O), and isopropanol (C3 H8 O). H2 was also produced, although the selectivity for products derived from the photoreduction of CO2 was significantly greater. The sample TiO2 /Cu 30% was significantly stable, which indicated the importance of an adequate heterojunction in the catalyst activity. These results demonstrate the synergistic effect between different copper species over TiO2, in which both materials play a role in the catalytic event. Graphical Abstract: ga1 Highlights: Cu-based heterojunctions showed a high reduction capacity. Cu decoration has increased the CH4 and CO evolution and H2 . The heterojunctions lead to different C1 and C2+ products. TiO2 acts as a charge separator and support for Cu 0 . TiO2 /Cu 30% showed significant stability during 7 successive cycles.