Highly Dispersed Pt Stabilized by ZnO_x-Si on Self-Pillared Zeolite Nanosheets for Propane Dehydrogenation

Abstract

Atomically dispersed metal catalysts can maximize the utilization of metals and provide unique chemical properties for catalytic reactions. However, the stabilities of high-loading metal clusters on solid supports are still under dispute, because small clusters are prone to agglomerate into larger particles at high temperature. Here, we prepared thermally stable highly dispersed Pt species immobilized by bridging Zn 2+ sites and silanol groups (Si-OH) on self-pillared silicalite-1 zeolite nanosheets (SP-S-1). The rotationally overgrown zeolite sheet-like structure provided a high specific surface area and abundant Si-OH, which favored atomically dispersed active sites with ZnO x -Si nanoclusters. The as-prepared PtZn/SP-S-1 exhibited a high specific activity of 1.23 mol C3H6 •g catal −1 • h −1 at 580 °C with propylene selectivity up to 99%. Moreover, no obvious deactivation was observed after 90 h on stream under a weight hourly space velocity of 15 h −1 . The self-pillared nanosheetsupported metal catalysts provide prospective guidance for high-temperature catalysis.

Recent Advances in Metal−Zeolite Catalysts for Direct Propane Dehydrogenation

“…The as-prepared sample showed high propylene selectivity and stability at 550 °C. The introduction of a second metal increased the electron density of the Pt active sites in Pt-based alloys, which weakened the binding energy of propylene and suppressed coke deposition. − Our previous work investigated the subsurface effect on the PtGa alloy for PDH (Figure b) . The PtGa alloy subsurface increased the electron density of surface Pt sites, thus decreasing the desorption energy of the propylene product.…”

A Cu-SiO2 Catalyst for Highly Efficient Hydrogenation of Methyl Formate to Methanol

“…There is a hypothesis that the Si-OH species contribute to the dispersion and stabilization of Cu nanoparticles during the calcination, reduction, and reaction processes. This phenomenon leads to increases in the Cu δ+ species and sintering resistance [46][47][48][49]. To verify this hypothesis, we used the TEM technique to measure the size of the Cu nanoparticles in the spent Cu-SiO2-CP and Cu-SiO2-AE catalysts.…”

“…In contrast, the constantly low methanol decomposition observed with the Cu-SiO2-AE catalyst indicates a sustained presence of Cu 0 species, which is consistent with the XRD and TEM results, showing a higher proportion of Cu δ+ There is a hypothesis that the Si-OH species contribute to the dispersion and stabilization of Cu nanoparticles during the calcination, reduction, and reaction processes. This phenomenon leads to increases in the Cu δ+ species and sintering resistance [46][47][48][49]. To verify this hypothesis, we used the TEM technique to measure the size of the Cu nanoparticles in the spent Cu-SiO 2 -CP and Cu-SiO 2 -AE catalysts.…”

Hydrothermal synthesis of highly cross‐linked PtZn@Silicalite‐1 structured catalysts for propane dehydrogenation

“…Pt‐based catalysts are widely applied in industrial PDH technologies owing to their superior activity of paraffinic CH bonds and limited extent of CC cleavage 3–5 . Over the past decades, significant progress has been made in the design and preparation of heterogeneous Pt‐based powder catalysts for PDH in fixed‐bed reactors 6–8 . Nevertheless, the random and loose loading of particulate adsorbent and catalytic materials in the fixed bed often results in uneven distribution.…”

“…[3][4][5] Over the past decades, significant progress has been made in the design and preparation of heterogeneous Pt-based powder catalysts for PDH in fixed-bed reactors. [6][7][8] Nevertheless, the random and loose loading of particulate adsorbent and catalytic materials in the fixed bed often results in uneven distribution. Reactants tend to flow through the fixed bed voids and generally suffer from low contact efficiency, and high resistance to mass transfer.…”