Electrical Stimulation of Catalytic Activity of Platinum Nanocoatings in CO oxidation

• Published in: Russian journal of physical chemistry. B 2020-05, Vol.14 (3), p.547-551
• Main Authors: Grishin, M. V., Gatin, A. K., Slutskii, V. G., Fedotov, A. S., Kharitonov, V. A., Shub, B. R.
• Format: Article
• Language: English
• Subjects: Carbon monoxide; Catalytic activity; Chemical Physics of Nanomaterials; Chemistry; Chemistry and Materials Science; Coating; External pressure; Oxidation; Physical Chemistry; Platinum; Polarity; Quantum chemistry
• ISSN: 1990-7931; 1990-7923
• DOI: 10.1134/S1990793120030033

— An increase in the rate of catalytic CO oxidation for platinum nanocoatings was measured when the electrical stress of various polarity and value was applied to a coating from an external source. Under conditions of the experiment at 250°C, atmospheric pressure and the starting composition mixture of 4.8% CO + 10.2% O 2 + Ar, applying the positive stress of +10 or +30 V on a coating leads to increase in the rate of CO oxidation by 18 or 54%, respectively. Applying the negative stress of –10 or –30 V leads to small acceleration in oxidation by 4 or 8%. It is shown that the effect of applied stress does not depend on particle size in a coating and grows linearly with stress. Quantum-chemical calculations of heats of association of CO and O 2 with electrically neutral or electrically charged platinum cluster were performed. It was found that the creation of the positive charge on Pt 2 leads to decrease in the heat of CO association by 6.4 kcal/mol and increase in the heat of O 2 association by 4.7 kcal/mol, while the creation of the negative charge on Pt 2 leads to a small effect of decrease in the heat of CO association by 3.0 kcal/mol and increase in the heat of O 2 association by 4.2 kcal/mol. From the results, it is proposed to explain increase in the rate of catalytic CO oxidation on platinum electrically charged with the help of the external stress source.