Energetics of CO(2)and H2O adsorption on alkaline earth metal doped TiO2

Autor(es)

da Silva, Andre Luiz ^[1] ; Wu, Lili ^{[2, 3]} ; Caliman, Lorena Batista ^[1] ; Castro, Ricardo H. R. ^[4] ; Navrotsky, Alexandra ^{[5, 6]} ; Gouvea, Douglas ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Met & Mat Engn, Polytech Sch, BR-05508030 Sao Paulo - Brazil

^[2] Univ Calif Davis, NEAT ORU, One Shields Ave, Davis, CA 95616 - USA

^[3] Univ Calif Davis, Dept Chem, One Shields Ave, Davis, CA 95616 - USA

^[4] Univ Calif Davis, Dept Mat Sci & Engn, One Shields Ave, Davis, CA 95616 - USA

^[5] Arizona State Univ, Sch Mol Sci, Tempe, AZ 85287 - USA

^[6] Arizona State Univ, Ctr Mat Universe, Tempe, AZ 85287 - USA

• Tipo de documento: Artigo Científico
• Fonte: Physical Chemistry Chemical Physics; v. 22, n. 27, p. 15600-15607, JUL 21 2020.
• Citações Web of Science: 5

Resumo

The process of CO(2)and H2O adsorption on the surface of nano-oxide semiconductors is important in the overall performance of artificial photosynthesis and other applications. In this study, we explored the thermodynamics of CO(2)and H2O adsorption on TiO(2)as a function of surface chemistry. We applied gas adsorption calorimetry to investigate the energetics of adsorption of those molecules on the surface of anatase nanoparticles. In an attempt to increase TiO(2)surface affinity to CO(2)and H2O, TiO(2)was doped with alkaline earth metals (MgO, CaO, SrO, and BaO) by manipulating the chemical synthesis. Adsorption studies using diffuse reflectance infrared spectroscopy at different temperatures indicate that due to the segregation of alkaline earth metals on the surface of TiO(2)nanoparticles, both CO(2)and subsequent H2O adsorption amounts could be increased. CO(2)adsorbs in two different manners, forming carbonates which can be removed at temperatures lower than 700 degrees C, and a more stable linear adsorption that remains even at 700 degrees C. Additionally to the surface energetic effects, doping also increased specific surface area, resulting in further improvement in net gas adsorption. (AU)

• Processo FAPESP: 13/23209-2 - Segregação de íons na superfície de nano-óxidos e sua influência no processo coloidal
• Beneficiário: Douglas Gouvêa
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 15/50443-1 - Interfaces in ceramic processing
• Beneficiário: Douglas Gouvêa
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 14/50279-4 - Brasil Research Centre for Gas Innovation
• Beneficiário: Julio Romano Meneghini
• Modalidade de apoio: Auxílio à Pesquisa - Programa Centros de Pesquisa em Engenharia