Simultaneous Site Adsorption Shift and Efficient CO Oxidation Induced by V and Co in Pt Catalyst

Ahmad, Rafia and Singh, Abhishek K (2017) Simultaneous Site Adsorption Shift and Efficient CO Oxidation Induced by V and Co in Pt Catalyst. In: JOURNAL OF PHYSICAL CHEMISTRY C, 121 (23). pp. 12807-12816.

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Abstract

A complete solution for CO poisoning of Pt catalysts requiries a design that entirely prevents CO adsorption On Pt :atoms. Here, we explore the CO adsorption sites and oxidation capability of 3d transition metal doped small magic clusters of Pt-4. Among Pt3M, only the: Pt3V freestanding cluster entirely eliminates the prospect of Pt poisoning by inverting the-adsorption site of CO to-V atom. The V d-band tenter lies closer to the Fermi level-than-that of Pt atoms, resulting. in a larger number of empty d-antib onding states, thereby making V comparatively more reactive toward `CO. The inversion of the CO adsorption site is also observed-for larger Pt V, clusters and becomes possible for PtnCOm, clusters for sizes larger than m + n = 12 atoms. Formation and removal of CO2 via the Langtnuir Hinshelwood mechanism occurs with low reaction barriers, exhibiting a high catalytic activity for the Pt (V/Co)(m), clusters. A maximum catalytic efficiency* attained for Pt41V14, which at room temperature gives a CO2 turnover frequency comparable to the conventional catalystS. The oxidation of CO becomes more favorable by the Mars van Krevelan mechanism for the cluster supported on vacancy prone Li-doped MgO(100). Our results present a rationale design of Pt poisoning free fuel cells and automobile exhaust catalysts, which can be entirely protected from CO poisoning and maintain lung term high catalytic efficiency.

Item Type:	Journal Article
Publication:	JOURNAL OF PHYSICAL CHEMISTRY C
Additional Information:	Copy right for this article belongs to the AMER CHEMICAL SOC, 1155 16TH ST, NW, WASHINGTON, DC 20036 USA
Department/Centre:	Division of Chemical Sciences > Materials Research Centre
Date Deposited:	14 Jul 2017 10:19
Last Modified:	14 Jul 2017 10:19
URI:	http://eprints.iisc.ac.in/id/eprint/57382

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