Dynamical Study of the Dissociative Chemisorption of CHD₃ on Pd(111)

Abstract

The specific reaction parameter (SRP) approach to density functional theory has been shown to model reactions of polyatomic molecules with metal surfaces important for heterogeneous catalysis in the industry with chemical accuracy. However, transferability of the SRP functional among systems in which methane interacts with group 10 metals remains unclear for methane + Pd(111). Therefore, in this work, predictions have been made for the reaction of CHD3 on Pd(111) using Born–Oppenheimer molecular dynamics while also performing a rough comparison with experimental data for CH4 + Pd(111) obtained for lower incidence energies. Hopefully, future experiments can test the transferability of the SRP functional among group 10 metals also for Pd(111). We found that the reactivity of CHD3 on Pd(111) is intermediate between and similar to either Pt(111) or Ni(111), depending on the incidence energy and the initial vibrational state distribution. This is surprising because the barrier height and experiments performed at lower incidence energies than investigated here suggest that the reactivity of Pd(111) should be similar to that of Pt(111) only. The relative decrease in the reactivity of Pd(111) at high incidence energies is attributed to site specificity of the reaction and to dynamical effects such as the bobsled effect and energy transfer from methane to the surface.

Computational approaches to dissociative chemisorption on metals: towards chemical accuracy

“…172 The DFMD 532 implementation of the BOMS model is in principle able to model all effects of (collective) surface phonon motion and of T s on S 0 . The method has been applied to achieve chemical accuracy for sticking of CHD 3 to Ni(111), 44 Pt(111), 47 and Pt(211), 47,84 with T s approximately equal to 500 K. More broadly, DFMD has been used to study the following systems in which a polyatomic molecule reacts with or is formed at a metal surface: sticking of CHD 3 on Ni(111), 44 Pt(111), 47,51,84,157,164 Pt( 110)-(2 Â 1), 182 Pt(211), 47,164,165 Pt(210), 181 Pd(111), 533 Cu(111), 63 Cu(211), 185 and single atom surface alloys of Cu (111), 185 of CH 4 on Ir(332), 534 of CH 3 OH on Cu(111), 183 of water on Ni (111), 184 of NH 3 on Ru(0001), 535 of CO 2 on Ni(100), 62,69,70 CO 2 formation through recombinative desorption from Pt(111) 462,534 and Pt(332), 534 and CO 2 formation through oxidation of surface adsorbed CO by impinging O-atoms on Pt (111). 536 DFMD has also been used to study systems in which a diatomic molecule reacts with a metal surface.…”

“…CHD 3 + Pd (111). S 0 computed with the SRP32-vdW1 DF for CHD 3 + Pd(111), 533 Pt(111), 47 and Ni (111) 44 are compared in Fig. 64.…”

“…64. The calculations for CHD 3 + Pd (111) 533 are also meant as predictions; their test by experiments could answer the question of whether the SRP-DF for CHD 3 + Pt (111) and Ni(111) (i.e., the SRP32-vdW1 DF) is also transferable to CHD 3 + Pd (111). The calculations predict that the reactivity of CHD 3 + Pd (111) should be intermediate between the other two systems, CHD 3 + Pt (111) and Ni (111).…”

Electronic friction coefficients from the atom-in-jellium model for Z=1–92

“…The appearance of a total spin and its effect on the friction coefficient can be understood by looking at the induced density of states [see Eqs. (11) and (13)] of vanadium (Z = 23) and cobalt (Z = 27) at r s = 3.5 in Fig. 5 for LDA and LSDA.…”

“…Therefore, the validity of the BO approximation has been questioned for a long time [4,5]. Even though ehp excitations have been neglected in many theoretical studies in the past, which could also explain experimental data [6][7][8][9][10][11][12], recent studies indicate that ehp excitations can play an important role in the dynamics of molecule-surface reactions [13][14][15][16][17][18][19][20][21][22]. For example, vibrational lifetimes of simple diatomic molecules adsorbed on metal surfaces were only explained by going beyond the BO approximation [17,[23][24][25][26][27][28][29][30][31][32][33][34].…”