Dissociation of CHD3 on Cu(111), Cu(211), and single atom alloys of Cu(111)

Abstract

In order to model accurately reactions of polyatomic molecules with metal surfaces important for heterogeneous catalysis in industry, the Specific Reaction Parameter (SRP) approach to density functional theory has been developed. This approach has been shown to describe the dissociation of CHD 3 on Ni(111), Pt(111), and Pt(211) with chemical accuracy. In this work, predictions have been made for the reaction of CHD 3 on Cu(111) and Cu(211) using barriers, elbow plots, and ab initio molecular dynamics. Future experiments could hopefully prove the transferability of the SRP functional to systems in which methane reacts with flat and stepped surfaces of adjacent groups of the periodic table, by comparison with our predictions. Moreover, the effect of a so-called single atom alloy on the reactivity of methane is investigated by making predictions for CHD 3 on Pt-Cu(111) and Pd-Cu(111). It is found that the reactivity is only increased for Pt-Cu(111) near the alloyed atom, which is not only caused by the lowering of the barrier height but also by changes in the dynamical pathway and reduction of energy transfer from methane to the surface.

Transferability of the SRP32-vdW specific reaction parameter functional to CHD3 dissociation on Pt(110)-(2 × 1)

“…14,27 The transferability of an SRP functional amongst different metals of the same group (group 10) of the periodic table has been demonstrated for methane dissociation, where the same SRP functional gives a chemically accurate description for the reaction of methane on Ni(111), 21,23,28 Pt(111), 23 and Pt(211). 23,29,30 This same SRP functional has recently been used to predict the reactivity of CHD 3 on Cu(111) and Cu(211), 31 and when experimental data become available, this will confirm whether the SRP functional is also transferable to methane dissociation on transition metals in other specific groups of the periodic table. The transferability of an SRP functional for a specific molecule reacting on a flat surface of a specific metal to that molecule interacting with a stepped surface of that metal is important for the accurate simulation of heterogeneously catalyzed reactions and can help with bridging the so-called structure gap in heterogeneous catalysis.…”

Accurate Probabilities for Highly Activated Reaction of Polyatomic Molecules on Surfaces Using a High-Dimensional Neural Network Potential: CHD3 + Cu(111)

“…9−11 However, the investigation of reactions with low reactivity (<1%) remains challenging due to the need for a large number of trajectories in combination with a large computational cost. 12 Therefore, neural network approaches have recently been employed in order to obtain results with the accuracy of AIMD using density functional theory (DFT), but with a considerably smaller computational cost. 13−18 So far, these studies either involved diatomic molecules 15−17,19 or they neglected the movement of surface atoms.…”

“…The neglect of surface motion can limit the accuracy of these studies due to the neglect of energy exchange between the molecule and the surface. 4,12,17,19,25−30 This lack of energy exchange represents a severe approximation for the dynamics of polyatomic molecules reacting on metal surfaces due to their high mass. 31,32 A modified Shepard interpolation method 33 has also been used to describe the potential of a polyatomic molecule reacting on a metal surface but again with the neglect of surface motion.…”

“…44 In total, 38 000 DFT data points were used to train the HD-NNP, of which 14 000 points were taken from an AIMD study. 12 Other data points included structures sampling the van der Waals well and transition state regions and the molecule’s vibrational modes. Finally, dynamically important structures missing from the data set were identified by running molecular dynamics (MD) on the (incomplete) HD-NNP and then added to the data set in a procedure described in ref (14).…”

An AIMD study of dissociative chemisorption of methanol on Cu(111) with implications for formaldehyde formation

“…For every AIMD data point, 500 trajectories were run, with a time step of 0.4 fs. The rest of the technical details of the AIMD calculations can be found in recent work 23,24,38,39 and in the supporting information. We use the SRP32-vdW functional previously used for CHD3 + Ni(111), Pt(111), Pt(211), Cu(111) and Cu(211) 23,24,39 , of which the exchange part is defined as…”