Large-scale DFT simulations towards catalytic hydrogenation reactions on supported PdC x nanoparticles Apostolos Kordatos 1 , Khaled Mohammed 1 , Reza Vakili 2 , Alexandre Goguet 2 , Haresh Manyar 2 , Emma Gibson 3 , Marina Carravetta 1 , Peter Wells 1 and Chris-Kriton Skylaris 1 1 University of Southampton, UK, 2 Queen’s University Belfast, UK, 3 University of Glasgow, UK Within heterogeneous catalysis, supported Pd nanoparticles (NPs) have been extensively investigated for their high activity towards many existing and emerging industrial applications [1-2] such as the selective hydrogenation and oxidation of unsaturated hydrocarbons. Pd-based catalysts tend to form carbide phases [3] during catalysis, thereby affecting the reaction process and thus, increasing their selectivity. Understanding the formation and stability [4] of carbidic Pd structures as well as the catalytic reaction mechanisms is crucial to establish their applicability in directed catalysis. In this study, atomistic simulations via the linear-scalingDensity Functional Theory code ONETEP [5] are performed to investigate the PdC x formation in Pd nanoparticles and provide insights on the reaction process of acetylene hydrogenation. Initially, the mechanisms of carbidisation in isolated NPs (as shown in Figure 1) are investigated through incorporation of C from the NP surface in the Pd octahedral interstitial sites. Furthermore, the interstitial-type diffusion of C after insertion is investigated in the subsurface region as well as towards the core of the NP. The PdC x formation at increasing C amounts for different geometries is also considered to estimate the maximum concentration in each structure. For the pristine Pd and PdC x structures, the hydrogenation of acetylene is investigated to provide insights of the potential role of the carbide phase in the catalytic process. To further explore the reaction mechanisms, we proceed towards supported NPs in large-scale systems of more than 1000 atoms as shown in Figure 2 . The scope of the work is to investigate the formation of carbidic phases in Pd NPs, provide advanced insights on reaction mechanisms and act synergetically with experimental methods in order to determine their applicability in catalysis.
References 1. Andrzej Borodziński and Geoffrey C. Bond, Catal. Rev. Sci. Eng., 2008, 50, 379. 2. R. Pellegrini, G. Agostini, E. Groppo, A. Piovano, G. Leofanti, C. Lamberti, J. Catal., 2011, 280, 150. 3. Ruiyun Guo, Qiang Chen, Xiang Li, Yaming Liu, Chaoqi Wang, Wei Bi, Caiyang Zhao, Yanjun Guo and Mingshang, Jin, J. Mater. Chem. A, 2019, 7, 4714. 4. Yucheng He and Chao Wu, J. Phys. Chem. C, 2021 125, 38, 20930. 5. Joseph C. A. Prentice, Jolyon Aarons, James C. Womack, Alice E. A. Allen, Lampros Andrinopoulos, Lucian Anton, Robert A. Bell, Arihant Bhandari, Gabriel A. Bramley, Robert J. Charlton, Rebecca J. Clements, Daniel J. Cole, Gabriel Constantinescu, Fabiano Corsetti, Simon M.-M. Dubois, Kevin K. B. Duff, José María Escartín, Andrea Greco, Quintin Hill, Louis P. Lee, Edward Linscott, David D. O’Regan, Maximillian J. S. Phipps, Laura E. Ratcliff, Álvaro Ruiz Serrano, Edward W. Tait, Gilberto Teobaldi, Valerio Vitale, Nelson Yeung, Tim J. Zuehlsdorff, Jacek Dziedzic, Peter D. Haynes, Nicholas D. M. Hine, Arash A. Mostofi, Mike C. Payne, and Chris-Kriton Skylaris, J. Chem. Phys., 2020, 152, 174111.
USC01
© The Author(s), 2023
Made with FlippingBook Learn more on our blog