In situ controlled promotion of catalyst surfaces via NEMCA: The effect of Na on the Pt-catalyzed NO reduction by H{sub 2}

Journal Article · Sat Mar 01 04:00:00 EST 1997 · Journal of Catalysis

DOI:https://doi.org/10.1006/jcat.1997.1551· OSTI ID:478761

Marina, O A; Yentekakis, I V; Vayenas, C G ^[1]

---

1. Univ. of Patras (Greece); and others

It was found that the catalytic activity and selectivity of Pt for NO reduction by H{sub 2} can be markedly and reversibly affected by depositing polycrystalline Pt films on {beta}{double_prime}-Al{sub 2}O{sub 3}, a Na{sup +} conductor, and applying external currents or potentials to supply or remove Na to or from the Pt catalyst surface. The increase in the rate of NO reduction to N{sub 2} is typically 10{sup 3}-10{sup 5} times larger than the rate of supply of Na and up to 30 times larger than the unpromoted rate. The use of the {beta}{double_prime}-Al{sub 2}O{sub 3} support permits precise in situ control of the Na coverage on the Pt surface. Sodium coverage of 0.06 cause up to 1450% increases in the total rate of NO reduction and enhance the selectivity to N{sub 2} from 30 to 75%. The promotional effect of Na is due to enhanced NO chemisorption and dissociation on the Pt surface. 43 refs., 9 figs.

• OSTI ID: 478761
• Journal Information: Journal of Catalysis, Journal Name: Journal of Catalysis Journal Issue: 2 Vol. 166; ISSN 0021-9517; ISSN JCTLA5
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
40 CHEMISTRY
ALUMINIUM OXIDES
CATALYSTS
CATALYTIC EFFECTS
CHEMISORPTION
HYDROGEN
NITRIC OXIDE
PLATINUM
REDUCTION