Zero-oxidation state precursor assisted fabrication of highly dispersed and stable Pt catalyst for chemoselective hydrogenation of α,β-unsaturated aldehydes

Abstract

The chemoselective hydrogenation of α, β-unsaturated aldehydes is a key strategy for the synthesis of fine chemicals. Herein, we developed an efficient method of depositing Pt particles on FeOx/SBA-15. This strategy is dependent on using a platinum-divinyltetramethyldisiloxane complex (Pt 0 -DVTMS) as the precursor, which we demonstrate can be removed through a H2-treatment under mild conditions. This, in turn, allowed for the synthesis of catalysts with well dispersed Pt particles. The presence of FeOx species also aided Pt dispersion; when coated onto SBA-15, FeOx strongly interacted with dissociated Pt species, inhibiting both Pt aggregation and metal leaching. Using cinnamaldehyde as a model α, β-unsaturated aldehyde, it was demonstrated that this catalyst was highly selective towards the unsaturated alcohol and no obvious loss in activity was observed over five recycles. This catalyst was determined to be significantly more effective than an analogous catalyst prepared using chloroplatinic acid as a precursor, evidencing the importance of using the Pt 0 -DVTMS precursor. We corroborate the excellent catalytic performance to highly dispersed Ptspecies, whereby Pt 0 and Pt 2+ play a critical role in activating H2 and the C=O bond. This research demonstrates that the Pt precursor can have a significant impact on the physicochemical properties and thus, the performance of the final catalyst. It also evidences how metal support interactions can dramatically influence selectivity in such hydrogenation reactions. This novel catalyst preparation protocol, using a DVTMS ligand for Pt impregnation, offers a facile approach to the design of multi-component heterogeneous catalysts.

Research Progress on Stability Control on Ni-Based Catalysts for Methane Dry Reforming

“…Therefore, for Ni-based c lysts in the DRM process, it is crucial to solve the problem of carbon deposition to main the activity and stability simultaneously. Sintering is the migration and agglomeration of the active metal at high temperatures, which reduces the number of active sites, resulting in a decrease in the activity of the catalyst [26]. The oxidation of active metals during the reaction and its reaction with the support or promoters, as well as the collapse of the pore structure of the catalyst support at high temperatures, will also cause catalyst deactivation.…”

Structural Design of Single‐Atom Catalysts for Enhancing Petrochemical Catalytic Reaction Process

“…The supported NiBi IMCscatalyst synthesized by Yu et al, [186] who has made a breakthrough in the preferential hydrogenation of various unsaturated aldehydes to C═O. Liang et al [187] reported Pt loading on FeO x /SBA-15 (Pt/FeO x /SBA-15), the presence of FeO x enhances the interaction between Pt and the carrier with the selectivity of 92% and yield of 89% for cinnamyl alcohol. In view of the difficulty of selective hydrogenation of 𝛽-unsaturated ketones to produce unsaturated alcohols 𝛼, Ouyang et al [188] reduced the particle size of the heteroge-neous catalyst from nanometers to clusters, propiophenone selective hydrogenation to unsaturated alcohols occurred on Au nanoclusters protected by precise sulfate of Au 25 (SR) 18 atoms, and showed selectivity of 100%.…”

“…Liang et al. [ 187 ] reported Pt loading on FeO x /SBA‐15 (Pt/FeO x /SBA‐15), the presence of FeO x enhances the interaction between Pt and the carrier with the selectivity of 92% and yield of 89% for cinnamyl alcohol. In view of the difficulty of selective hydrogenation of β‐unsaturated ketones to produce unsaturated alcohols α, Ouyang et al.…”

Zn-single atom catalysts enable the catalytic transfer hydro-genation of α,β-unsaturated aldehydes

“…Generally, two parameters, catalytic performances (conversion and selectivity) and costs of catalysts, are mainly considered for the desirable catalysts. 9 The precious metal-based catalysts, such as Pt, Au, Ag, Ir, Ru, Rh, Os and Pd, have been widely explored toward CTH reaction of α, β-unsaturated aldehydes 4,[17][18][19] . However, their high costs and somewhat unsatisfactory selectivity limit their wide applications.…”