Mechanistic insight into the hydrogenation of acetylene on the Pd2/g-C3N4 catalyst: effect of Pd clustering on the barrier energy and selectivity

Abstract

In this work, the hydrogenation of acetylene on the Pd 2 /g-C 3 N 4 catalyst is investigated by the Density Functional Theory (DFT) and Quantum Theory of Atoms in Molecules (QTAIM) calculations. The Prereactant (R), transition states (TSs), and the intermediates (IMs), involved in the hydrogenation process, are characterized from the point of view of energy and structure. The calculated energy barrier for the hydrogen transfer to the acetylene and ethylene are 6.77 and 12.28 kcal/mol, respectively which shows that the Pd 2 /g-C 3 N 4 catalyst has good selectivity for the conversion of acetylene to ethylene rather than ethane. Comparing the values of these energy barriers with those of the hydrogenation of acetylene on the Pd/g-C 3 N 4 catalyst (21.53 and 38.88 kcal/mol, respectively) shows that the increase in the number of the Pd atoms decreases the energy barriers of the hydrogenation reaction and increases the selectivity of the catalyst for the ethylene production.

Selectivity-Enhanced Electroreduction of CO2 to CO at Novel Ru-Linked-GO Nanohybrids: the Role of Nanoarchitecture

“…The calculations for determining the molecular geometry and electronic structure of RCMP were performed using the Gaussian 09 Quantum Chemistry package. − The structure of RCMP was optimized by DFT (density functional theory) and employing the B3PW91 functional and the SDDall basis set in the gas phase for all atoms. , The frequency calculations were carried out on the optimized structure to check its correct positions on potential energy levels and determine its electronic energies. The energy levels and shapes of the molecular orbitals, the HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital), were obtained to investigate the donor–acceptor properties of the RCMP structure at the same level of theory.…”

Theoretical study of the electronic structure of the complexes of gold, silver, and copper mono- and bimetallic nanoclusters decorated on graphitic carbon nitride (g-C3N4): DFT and TD-DFT studies of photocatalytic activity

“…Many researchers have investigated the influence of metalsupport interactions on the catalytic performance through computational and experimental studies. 12,[27][28][29][30][31][32][33][34] Nevertheless, since reaction conditions usually change the properties of heterogeneous catalysts, it is more complicated to acquire detailed data regarding their structure by experimental methods. 35 In this regard, computational modeling adopting quantum mechanical (QM) techniques, for instance, density functional theory (DFT), appears to be practicable for overcoming the experimental constraints.…”