The evolution of single-site Pd1/AC catalyst during the process of acetylene dialkoxycarbonylation

Palladium and Ruthenium Dual‐Single‐Atom Sites on Porous Ionic Polymers for Acetylene Dialkoxycarbonylation: Synergetic Effects Stabilize the Active Site and Increase CO Adsorption

“…Scanning electron microscopy (SEM) of PIPs and Pd 1 À Ru 1 / PIPs (Figure S2a and Figure S2b) further confirmed the existence of a hierarchical pore structure, which was beneficial for the dispersion of active species and mass transfer-especially for catalytic reactions involving small gas molecules. Compared to activated carbon with a majority of micropores, [2] this pore structure could delay the blockage of carbon deposits, thus maintaining better catalytic stability. In addition, thermogravimetric analysis (TGA) implied that the PIPs and Pd 1 À Ru 1 /PIPs catalysts possess good thermal stability with a pyrolytic temperature of 673 K (Figure S3).…”

“…Even so, HSMSC still suffer from various limitations, and especially poor stability of the coordination structure under a relatively harsh environment. For example, the single‐Pd II site is easy to reduce or even agglomerate into inactive Pd black during a carbonylation reaction process in the presence of CO atmosphere [2] . As an extension of HSMSC, dual‐single‐metal‐sites catalysts (DSMSC) may overcome the limitations of HSMSC and they have potential for multiple catalytic reactions [3] .…”

“…For example, the single-Pd II site is easy to reduce or even agglomerate into inactive Pd black during a carbonylation reaction process in the presence of CO atmosphere. [2] As an extension of HSMSC, dual-singlemetal-sites catalysts (DSMSC) may overcome the limitations of HSMSC and they have potential for multiple catalytic reactions. [3] However, the development of stable DSMSC via a feasible and practical fabrication method is still in its infancy.…”

Alloying Iron into Palladium Nanoparticles for an Efficient Catalyst in Acetylene Dicarbonylation

“…One of these, acetylene dicarbonylation, provides a cost-effective way to synthesize α, β-alkynyl esters, unsymmetrical maleate esters, and their derivatives [ 4 ]. Heterogeneous catalysts are one of the promising replacers for homogeneous catalysts despite various supported Pd catalysts being designed, such as Pd 1 /AC ([Pd(CO)I 4 (O=AC)] 2− ) [ 5 ], Pd/AC (nanosheet) [ 6 ], and Pd/Fe 2 O 3 [ 7 , 8 ], which have good activity and selectivity. However, it has been reported that supported Pd nano-catalysts are more likely to generate soluble metal carbonyl species and experience severe metal leaching in high-pressure CO reactions [ 9 ].…”

“…However, it has been reported that supported Pd nano-catalysts are more likely to generate soluble metal carbonyl species and experience severe metal leaching in high-pressure CO reactions [ 9 ]. In addition, the catalytic performance of supported Pd catalysts relies mainly on the surface structure and shape of the active metal, as well as the type and micromorphology of the carrier [ 5 , 6 , 7 , 8 ].…”