A DFT Study on the Catalytic CO Oxidative Coupling to Dimethyl Oxalate on Al-Doped Core–Shell Pd Clusters

Abstract

A series of core–shell catalysts aiming at CO oxidative coupling to dimethyl oxalate (DMO) were constructed, and effects of the second metal doping and surface structures on the reaction activity and favorable reaction path were investigated by using the density functional theory (DFT) method. Pd13, Al@Pd12, and Ag@Pd12 were first studied to find the proper doping metal. Our results showed that the activity of CO oxidative coupling to DMO follows the order of Al@Pd12 > Pd13 > Ag@Pd12, and the same result was also obtained via the electronic analysis. In addition, Al6@Pd32 and Al13@Pd42 catalysts with higher doping ratio and lower cost than that of Al@Pd12 were selected to examine the influence of surface structure on the reaction activity. It showed that CO + CH3O → COOCH3 + CO → OCCOOCH3 + CH3O → DMO is the favorable pathway on the (100) surface of Al6@Pd32 catalyst, while CO + CH3O → CO + CH3O (COOCH3) → COOCH3 + COOCH3 → DMO is the optimal pathway on the (111) surface of Al@Pd12 and Al13@Pd42, which indicated that the surface structure of catalysts affected the preferable pathway of DMO formation. Moreover, activities of CO oxidative coupling to DMO on AlPd core–shell catalysts followed the order of Al@Pd12 > Al13@Pd42 > Al6@Pd32. In addition, Al13@Pd42 also exhibited a good selectivity between DMO and DMC. Thus, Al13@Pd42 is a proper catalyst with high activity, high selectivity, and low cost because of high Al:Pd ratio.

One-Pot Synthesis of Au/Pd Core/Shell Nanoparticles Supported on Reduced Graphene Oxide with Enhanced Dehydrogenation Performance for Dodecahydro-N-ethylcarbazole

“…Moreover, similar conclusions have also been verified by the relevant DFT calculations. Surface electronic properties of precious metal core/shell nanostructures were investigated to explain the effects on catalytic activity. ,− ,, Charge transfer between atoms, ε HOMO variation, coverage differences, d-band center shift, and other changes in surface electronic structures caused by different core/shell combinations will have a huge impact on different reactions.…”

“…Generally, a core/shell structure shows enhanced catalytic properties relative to their alloy because of its highly functional architecture . The energetic and electronic properties of different elements and compositions were already investigated by density functional theory to confirm the superior activity of the core/shell structure, and it was found that properties such as Fermi energy and d-band center were strongly correlated with the activity for different reactions. − However, the synthesis of bimetallic core/shell components is a complex process, and hence, there are various strategies available for producing different kinds of catalysis . A multistep seed-mediated method is often used to form the regular core/shell structure. − In a relatively simple one-pot preparation, surfactants, − ionic liquids, , etc.…”

Direct Synthesis of Ethylene Glycol from Syngas

“…In the past 20 years, many research groups have carried out detailed research on this topic. [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] Similarly, in the hydrogenation of DMO, the performance of Cu catalyst is also the most critical part. In the past few years, researchers have also conducted in-depth research on this key technology.…”

Thermodynamic Modeling of the Al–Co–Pd Ternary System, Aluminum Rich Corner

“…Thermodynamic assessment for the Al-Co-Pd ternary system has not yet been published. However, the system is of interest for the possible use of the Al-Pd based materials, for example, for catalysts [1] or as coatings with good oxidation resistance, low adhesion and high hardness [2][3][4] and also in electronics as semiconductors [5,6]. In addition, the system is also interesting from a scientific point of view because it contains a large number of complicated intermetallics, quasicrystals and quasi-crystalline approximants [7,8].…”