Geometric stability and reaction activity of Pt clusters adsorbed graphene substrates for catalytic CO oxidation

Abstract

The geometric stabilities, electronic structures and catalytic properties of tetrahedral Pt4 clusters anchored on graphene substrates are investigated using the first-principles methods. It is found that the small Pt4 clusters adsorbed on pristine graphene substrates easily interconvert between structural isomers by the small energy barriers, while the structural interconversion of Pt4 clusters on the defective graphene and oxygen-doped graphene (O-graphene) have the large energy barriers. Compared to other graphene substrates, the Pt4 clusters supported on the O-graphene substrate (Pt4/O-graphene) have the least geometrical distortion and the high symmetry of the Pt4 cluster can enhance the sensitivity of reactive gases. Moreover, the sequential reactions of CO oxidation on Pt4/O-graphene are investigated for comparison. Compared with the coadsorption reaction of CO and O2 molecules, the dissociative adsorption of O2 as a starting step has a small energy barrier (0.07 eV) and is followed through the Eley-Rideal reaction with an energy barrier of 0.42 eV (CO + Oads → CO2). The results provide valuable guidance for fabricating graphene-based catalysts as anode materials, and explore the microscopic mechanism of the CO oxidation reaction on atomic-scale catalysts.

First Principles Study on the CO Oxidation on Mn-Embedded Divacancy Graphene

“…Due to the high cost and high reaction temperature of these noble metals, it is desirable to develop noble-metal-free catalysts for CO oxidation at low temperature. Noble metal clusters on supports are further studied to decrease the reaction barriers for CO oxidation (Tang et al, 2015 ; Ma et al, 2016 ; Wang et al, 2016 ; Ali et al, 2017 ; Chen et al, 2017 ). Furthermore, single atom catalyst decorated on appropriate matrix is attracted a lot of interests due to the excellent catalytic performance (Dvorák et al, 2016 ; Jones et al, 2016 ).…”

Optical response and gas sequestration properties of metal cluster supported graphene nanoflakes

“…It has been proposed that graphene can be used in engineering fuel cells, energy storage devices, nanoelectronics, optoelectronic devices, gas sensors, etc. [16][17][18][19][20] Apart from the quest for understanding cluster-surface interaction from a fundamental point of view and thus elucidating the nature of binding, such a study also serves as an ideal platform to test the changes being imparted on the electronic properties of the host surface due to the interaction between the host and the guest. [3][4][5][6][7] The major bottleneck in an even wider application of graphene is related to its unique electronic structure which causes it to possess very small density of states close to the Fermi level.…”

Insight into the mechanism of Pt anchored graphene toward the CHx(x = 1 ∼ 4) reforming under H2 environments

“…The catalysts are desired to disperse finely on graphene due to its high surface area [22e25] and display high catalytic activity [26e29]. Recently, the experimental and theoretical results demonstrated that small Pt clusters on graphene have better catalytic activity for oxygen reduction reaction (ORR) [30e32], hydrogen storage [33,34] and CO oxidation [23,24,35,36]. However, the migration of nanosized catalyst particles causes their potential accumulation into larger structures, which limit their availability and activity [37,38].…”