Antisintering Pd₁ Catalyst for Propane Direct Dehydrogenation with In Situ Active Sites Regeneration Ability

Abstract

Atomically dispersed Pd (Pd 1 ) catalysts supported on annealed nanodiamond were prepared through a deposition−precipitation method toward propane direct dehydrogenation (PDDH). The Pd 1 catalyst is superior to Pd cluster/particle catalysts in activity and stability. Combining experimental characterizations and DFT calculations revealed that atomically dispersed Pd species have strong interactions with the hybrid nanodiamond/graphene support, leading to better resistance to coke formation. More importantly, Pd sintering is inevitable in the cluster/particle catalysts, while the high dispersion of Pd species in Pd 1 catalyst is well-preserved during the reaction, which is caused in part by the redistribution or migration of Pd single atoms onto the carbonaceous compound (coke). As a result, the Pd 1 catalyst shows significantly better activity and stability in high-reaction temperatures than Pd cluster/particle catalysts. This work reveals deeper insights on designing highly dispersed metal catalysts with the ability of in situ regeneration of active sites in high-temperature catalytic reactions.

Promoting Catalytic Activity of Boron by Phosphor in Propane Oxidative Dehydrogenation

“…1,2 Propylene is primarily produced by direct dehydrogenation (DH), which is endothermic, equilibrium limited, and requires significant energy input. 3 Currently, the propane dehydrogenation (PDH) is considered as an economically and environmentally friendly route to produce about 10% of the global propylene. 4 The direct DH is endothermic in nature; to achieve acceptable conversion and high yield of target olefins, substantial energy input and high temperature are required, and the overall energy efficiency is limited.…”

“…Propylene is regarded as one of the most important building blocks for producing polypropylene, propylene oxide, acrylonitrile, and related chemicals. , Propylene is primarily produced by direct dehydrogenation (DH), which is endothermic, equilibrium limited, and requires significant energy input . Currently, the propane dehydrogenation (PDH) is considered as an economically and environmentally friendly route to produce about 10% of the global propylene .…”

Oxidative dehydrogenation of cyclohexene on atomically precise subnanometer Cu4−nPdn (0 ≤ n ≤ 4) tetramer clusters: the effect of cluster composition and support on performance

“…82-84, 95, 96 Moreover, aggregation can be an additional factor, even though, we did not observe Pd agglomerates on AFM images, one cannot fully exclude agglomeration to some extent It was also shown that Pd 1 is stable on nanodiamonds under propane dehydrogenation conditions. 63 Catalytic performance of the Cu 1 Pd 3 , Cu 2 Pd 2 and Cu 3 Pd 1 mixed tetramers on TiO 2 support From the UNCD and ZrO 2 -supported mixed four-atom clusters, only the zirconia-supported Cu 1 Pd 3 , Cu 2 Pd 2 and Cu 3 Pd 1 tetramers produced cyclohexadiene, moreover, exhibiting a strongly composition-dependent selectivity for C6 products cyclohexadiene and benzene. In order to further explore the effect of support, a reducible oxide support TiO 2 was chosen to complement the UNCD and the non-reducible zirconia supports.…”

Revealing the promotion of carbonyl groups on vacancy stabilized Pt4/nanocarbons for propane dehydrogenation

“…4 The subnanometric Pt clusters can achieve maximum atomic utilization, reduce the active sites for side reactions and enhance propylene desorption. [5][6][7] Nevertheless, Pt clusters are prone to agglomeration or sintering at the high temperature of PDH (4550 1C), owing to the relative high surface free energies. Therefore, maintaining the stability of Pt clusters remains a challenge, which can be overcome by finding appropriate anchoring supports.…”

“…In the works of Liu's group, they synthesized core-shell nanodiamond@graphene hybrid supports to anchor Pt nanoparticles or clusters for alkane dehydrogenation. 5,8,[16][17][18] The results showed that Pt clusters would bind strongly with the C atoms around vacancies, thus enhancing the interaction between Pt clusters and supports. Meanwhile, our previous theoretical work 19 systemically designed carbon materials with various vacancies to anchor the Pt single atom for PDH.…”