Water Dissociation on Pt Nanoparticles Adsorbed on Carbon Nanotubes: a DFT Study.

JOSÉ L. NUÑEZ; GUSTAVO D. BELLETTI; IONUT TRANCA; FREDERIK TIELENS; PAOLA M. QUAINO

Bruselas

Conferencia; 19th International Conference on Density Functional Theory and its Applications (DFT 2022); 2022

Inthis work, the deposition of Ptn nanoparticles (n = 1, 3, 7) on a (5,5) carbon nanotube (CNT) support, as well as their role as catalystsin the water dissociacion reaction, were analyzed by means of densityfunctional theory (DFT).PeriodicDFT calculations were performed with the VASP code, which includedlong range (van der Waals) interactions considered within the DFT-D3approach. For the water dissociation reaction, the nudged elasticband (NEB) method was used to find minimum energy paths and thecorresponding activation energy barriers.Theresults of a methodical analysis of platinum nanostructures andinsertion sites shows that the hybrid Ptn /CNT systems areenergetically stable (with interaction energies ranging from −1.0eV to −3.6 eV) and exhibit charge redistribution –especially onthe deposited metal clusters– that affects their reactivity.[1] Thenature of the deposited Pt particles sizes and geometries, along withcharge accumulation due to their interaction with the CNT, led to lowactivation energy barriers for the water dissociation reaction,compared to those reported for Pt(111) surfaces (0.78 eV). [2] Figure1 shows the initial (left), transition (middle) and final (right)states for a particular reaction path over a Pt3 /CNT system, whichshowed a remarkably low energy barrier (0.30 eV).[1]TheDFT methods described above allows us to obtain an atomic-scaleinsight of the adsorption and dissociation processes, yelding resultsthat suggest a double benefit in the material performance as anelectrocatalyst: the decrease in the energy barrier for the waterdissociation, and the use of lower amounts of the precious metal onmodern catalysts.References1.J. L. Nuñez, G. D. Belletti, F. Tielens, P. M. Quaino. Top. Catal.,2022. DOI: 10.1007/s11244-022-01613-6.2.J. L. Fajín, M. N. Cordeiro, J. R. Gomes. J. Chem. Phys. A, 2014,118(31), 5832.p { margin-bottom: 0.1in; line-height: 115%; background: transparent }a:link { color: #000080; so-language: zxx; text-decoration: underline }