Effect of the size of Cu clusters on selectivity and activity of acetylene selective hydrogenation

Dynamics of Initial Hydrogen Spillover from a Single Atom Platinum Active Site to the Cu(111) Host Surface: The Impact of Substrate Electron–Hole Pairs

“…Taking advantage of hydrogen spillover, Sykes and co-workers recently created single atom alloys (SAAs) by doping copper with atomically dispersed platinum group metals (PGMs, e.g ., Pd and Pt), − which are found to catalyze selective hydrogenation of alkenes. , It is well established that Cu surfaces exhibit high catalytic selectivity toward alkene hydrogenation, , but H 2 dissociation on pure Cu has a high activation barrier and occurs very slowly unless driven by harsh reaction conditions such as high temperatures and pressures . Single atoms of a PGM alloyed into Cu surfaces can significantly improve the activity of the catalyst yet retaining its high reaction selectivity in hydrogenation reactions.…”

Relative Populations and IR Spectra of Cu38 Cluster at Finite Temperature Based on DFT and Statistical Thermodynamics Calculations

“…Its lowest IR active vibration frequency is 32.57 cm −1 and it is a semiconductor with an electronic gap of 0.623 eV. Previous works regarding the exploration of the potential energy surface of Cu 38 using genetic algorithms via the Gupta potential have often found highly symmetric TO structures ( Kostko et al, 2005 ; Darby et al, 2002 ), which have also been reported using the Sutton-Chen potential with Monte Carlo simulations ( Zhao et al, 2017 ). The optimized Cu-Cu bond length is 2.4670 Å, which is in good agreement with the reported bond length in the Cu-Cu dimer via DFT calculations (2.248 Å) ( Kabir et al, 2004 ; Guvelioglu et al, 2006 ) and is consistent with the experimental Cu-Cu bonding distance of 2.22 Å ( Kabir et al, 2004 ).…”

“…Its lowest IR active vibration frequency is 32.57 cm −1 and it is a semiconductor with an electronic gap of 0.623 eV. Previous works regarding the exploration of the potential energy surface of Cu 38 using genetic algorithms via the Gupta potential have often found highly symmetric TO structures (Kostko et al, 2005;Darby et al, 2002), which have also been reported using the Sutton-Chen potential with Monte Carlo simulations (Zhao et al, 2017).…”

“…Several authors used an empirical potential-energy function containing two-body atomic interactions and found that fivefold symmetry appears to be the putative global minimum in the Cu 38 cluster ( Erkoç, 1994 ; Erkoç and Shaltaf, 1999 ). In contrast, previous studies reported the cuboctahedron structure as the putative global minimum ( Grigoryan et al, 2006 ) by employing empirical many-body Gupta and Sutton-Chen potentials; some other works also consider the Cu 38 octahedron cluster to be the putative global minimum ( Itoh et al, 2009 ; Hijazi and Park, 2010 ; Takagi et al, 2017 ), but several others found that the Cu 38 cluster with truncated octahedron geometry is energetically more stable than other configurations ( Darby et al, 2002 ; Itoh et al, 2009 ; Hijazi and Park, 2010 ; Núnez and Johnston, 2010 ; Park and Hijazi, 2012 ; Fernández et al, 2015 ; Zhao et al, 2017 ). Some of us pointed out that the energies computed via different methods such as DFT, second-order Møllet-Plesset approach (MP2), and Coupled cluster with single-double and perturbative triple (CCSDT) excitations yield different energetic ordering results ( de la Puente et al, 1997 ; Buelna-Garcia et al, 2021 ; Buelna-Garcia et al, 2021 ; Castillo-Quevedo et al, 2021 ).…”

Structures and stability of the Cu$_{38}$ cluster at finite temperature

“…In contrast, the cuboctahedron structure was reported as putative global minimum in a previous studies 25 employing empirical many-body Gupta and Sutton-Chen potentials. Nevertheless, there has been some discussion which is the lowest energy structure, some previous works consider the Cu 38 octahedron cluster, as the putative global minimum 18,20,21 , in contrast, several others found that Cu 38 cluster with the truncated octahedron geometry is energetically more stable than other configurations 20,21, [26][27][28][29][30] . We point out that the energy computed with different methods such as DFT, MP2, or CCSDT, just to mention few of them, yield different energetic ordering.…”