Superior catalytic performance of Pd-loaded oxygen-vacancy-rich TiO2 for formaldehyde oxidation at room temperature

• Published in: Journal of catalysis Vol. 396; pp. 122 - 135
• Main Authors: He, Miao, Cao, Yueqiang, Ji, Jian, Li, Kai, Huang, Haibao
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01-04-2021
• Subjects: Electronic metal–support interaction; Formaldehyde oxidation; Reduced TiO2; Surface oxygen vacancies; Synergistic effect; Electronic metal–support interaction; Formaldehyde oxidation; Reduced TiO2; Synergistic effect; Surface oxygen vacancies
• ISSN: 0021-9517; 1090-2694
• DOI: 10.1016/j.jcat.2021.01.035

Reduced TiO2 with abundant oxygen vacancies induced negatively charged Pd nanoparticles via electronic metal-support interaction and showed a synergistic effect with the electronically modulated Pd to realize superior catalytic activity toward formaldehyde oxidation at room temperature.
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•Pd-loaded oxygen vacancy-rich TiO2 exhibited superior catalytic performance for HCHO oxidation at room temperature.•TiO2 with rich oxygen vacancies induced geometric effect on Pd nanoparticles by lowering the particle size.•A remarkable electronic metal-support interaction between Pd and the defective TiO2 was induced.•Electronically modulated Pd nanoparticles and the support showed synergistic effects on the catalytic performance.
Modulating the metal–support interaction is a promising way to tailor the electronic structure of metal nanoparticles and hence alter their catalytic performance. Here, we developed a reduced TiO2 with rich oxygen vacancies on which to load Pd for catalytic oxidation of formaldehyde (HCHO) at room temperature. The reduced TiO2 remarkably induced an electronic metal–support interaction by transferring electrons from the support to Pd to form negatively charged Pd nanoparticles, facilitating the oxygen association. Simultaneously, the reduced TiO2 significantly increased the dispersion and the reduction degree of Pd compared with the pristine TiO2 by offering more anchor sites and electron-rich sites. Furthermore, the abundant oxygen vacancies in the reduced TiO2 show a synergistic effect by enabling the effective adsorption and dissociation of water to generate surface hydroxyl groups, accelerating the kinetics of active oxygen species generation and promoting the complete conversion of 100 ppm HCHO at a WHSV of 120,000 mL/(gcat·h). We tentatively propose two reaction mechanisms for HCHO oxidation over Pd-loaded oxygen-vacancy-rich TiO2 involving active oxygen species.