Single-atom Pd sites on the surface of Pd–In nanoparticles supported on γ-Al 2 O 3 : a CO-DRIFTS study

Highly-Ordered PdIn Intermetallic Nanostructures Obtained from Heterobimetallic Acetate Complex: Formation and Catalytic Properties in Diphenylacetylene Hydrogenation

“…Further selectivity improvement observed for the catalyst reduced at higher temperatures is attributable to the progressive formation of Pd 1 In 1 nanoparticles predominating in the catalysts reduced at 400–600 °C. The suggestion is in good agreement with the data on the excellent selectivity of PdGa [ 6 , 10 ] and PdIn IMCs in selective acetylene hydrogenation [ 15 ], and the observed selectivity improvement can be explained by isolation of Pd sites by inactive In atoms [ 13 , 15 ], and modification of their electronic structure similarly to PdGa IMC [ 10 , 61 ].…”

“…Previously, it was shown that the concept of site-isolated catalysts is also applicable for the catalysts containing PdIn IMCs. Our recent data of Diffuse reflectance infrared fourier transform spectroscopy of adsorbed CO (CO-DRIFTS) revealed the presence of isolated palladium atoms surrounded by indium on the surface of PdIn intermetallic nanoparticles [ 13 ]. It was also found that PdIn catalysts demonstrate high selectivity in the liquid-phase hydrogenation of internal alkynes comparable with that of the commercial Lindlar catalyst.…”

Local Structure of Pd1 Single Sites on the Surface of PdIn Intermetallic Nanoparticles: A Combined DFT and CO-DRIFTS Study

“…These observations are in a good agreement with the data reported by Furukawa [27], Hirano [33], and results of our previous studies [18,35], and indicate that multiple coordination of CO on the surface of PdIn intermetallic nanoparticles is unfavorable. As mentioned above, this observation can be explained by the disappearance of Pd n ensembles (n ≥ 2) on PdIn surface [27,33] capable of accommodating bridged CO species [35] similarly to the PdGa IMCs [22]. This idea is in line with the results of detailed study of bulk structure and physical properties of InPd IMC [21].…”

“…Similar observations were presented elsewhere [33,34]. Results of our previous CO-DRIFTS study of Pd 1 In 1 /Al 2 O 3 are in good agreement with these data and demonstrate the disappearance of multiply-bonded CO species on the surface of PdIn nanoparticles [18,30,35]. However, it is still unclear which characteristic features of PdIn surface structure impede the multipoint adsorption of CO.…”

Газофазное И Жидкофазное Гидрирование Ацетилена В Обедненных И Обогащенных Смесях На Нанесенных Модифицированных Палладиевых Катализаторах

“…Однако, при этом, активные центры преимущественно представлены А-типом, что, соответственно, увеличивает селективность процесса [3,47,67,77,78,[85][86][87]. В ряде работ [57,88] показано, что модифицирование может приводить к формированию уникальных поверхностных структур с изолированными активными центрами, где одиночные атомы палладия окружены атомами модификатора. Такая конфигурация поверхности благоприятствует адсорбции ацетилена преимущественно в π-форме и, следовательно, заметному увеличению селективности по этилену.…”