In Situ Encapsulation of Pt Nanoparticles within Pure Silica TON Zeolites for Space-Confined Selective Hydrogenation

Abstract

Straightforward encapsulation of Pt clusters (∼2 nm) into the pure silica TON-type zeolite (ZSM-22) was reached in a dry gel conversion route, where the ionic liquid template was removed via the hydrocracking-calcination-reduction approach. The obtained Pt@ZSM-22 series possessed high crystallinity, large surface area, and ultrafine Pt clusters inside the zeolite crystals. They exhibited remarkable activity in the semi-hydrogenation of phenylacetylene into styrene; the lead sample with 0.2 wt % Pt loading afforded a large turnover number up to 117,787. The preferential high affinity of the pure silica ZSM-22-encapsulated Pt clusters toward the substrate phenylacetylene rather than the hydrogenated product was derived from the unique space-confinement effect of zeolite microchannels, which is responsible for such excellent performance.

Promotion Effect of the X-Zeolite Host on Encapsulated Platinum Clusters for Selective Hydrogenation of Phenylacetylene to Styrene

“…Selective catalytic hydrogenation among various catalytic processes is a kind of important reaction, as it produces high-value chemicals through the control of the hydrogenation degree of a low-value reactant. − The process of phenylacetylene semihydrogenation is of great significance because phenylacetylene is considered to be a harmful feedstock for polystyrene industrial production in the polymerization process of styrene. − Therefore, it is desired to achieve a high selectivity of styrene while keeping a high conversion of phenylacetylene during the reaction process. It is generally accepted that palladium catalysts are mostly used to achieve a high catalytic performance for this reaction.…”

A Magnetically Separable Pd Single‐Atom Catalyst for Efficient Selective Hydrogenation of Phenylacetylene

“…Styrene, a crucial chemical intermediate, is widely used in rubber, pharmaceuticals, agrochemicals, pigments, and other industrial fields. [ 1,2 ] Extracting styrene from cracked petroleum is one of the most promising methods for styrene production, due to its lower cost and readily available raw materials. Nevertheless, phenylacetylene as a harmful impurity in styrene feedstock is gradually enriched during the process of extraction, leading to the poisoning of subsequent procedure of styrene polymerization.…”

“…Styrene, a crucial chemical intermediate, is widely used in rubber, pharmaceuticals, agrochemicals, pigments, and other industrial fields. [1,2] Extracting styrene from cracked petroleum is one of the most promising methods for styrene Surface modification, such as adding a second metal (Pb, Sn, et al) or organic reagents, [15][16][17] is a common strategy. While, the improvement of selectivity was at the cost of activity, as a result that a large ratio of active sites was covered and inaccessible to reactants.…”

Fabrication of Superamphiphilic Carbon Using Lignosulfonate for Enhancing Selective Hydrogenation Reactions in Pickering Emulsions

“…Then, the as-prepared superamphiphilic carbon was used in Pickering emulsion catalysis. Selective hydrogenation of olefins in the liquid–liquid biphasic system is usually employed as a model reaction to appraise the catalysis efficiency. − In this study, styrene, phenylacetylene, and cis -stilbene were selected as reactants and Pd/C was used as the catalyst. As shown in Figure a, conversions and yields for hydrogenation of styrene to ethylbenzene, hydrogenation of phenylacetylene to styrene, and hydrogenation of cis -stilbene to diphenylethane using superamphiphilic carbon were much higher than those without superamphiphilic carbon.…”