Zeolite‐Encaged Pd–Mn Nanocatalysts for CO₂ Hydrogenation and Formic Acid Dehydrogenation

Abstract

AC O 2-mediated hydrogen storage energy cycle is ap romising wayt oi mplement ah ydrogen economy,b ut the exploration of efficient catalysts to achieve this process remains challenging.H erein, sub-nanometer Pd-Mn clusters were encaged within silicalite-1 (S-1) zeolites by al igand-protected method under direct hydrothermal conditions.T he obtained zeolite-encaged metallic nanocatalysts exhibited extraordinary catalytic activity and durability in both CO 2 hydrogenation into formate and formic acid (FA) dehydrogenation backt oC O 2 and hydrogen. Thanks to the formation of ultrasmall metal clusters and the synergic effect of bimetallic components,t he PdMn 0.6 @S-1 catalyst afforded af ormate generation rate of 2151 mol formate mol Pd À1 h À1 at 353 K, and an initial turnover frequency of 6860 mol H 2 mol Pd À1 h À1 for CO-free FA decomposition at 333 Kw ithout any additive.B oth values represent the top levels among state-of-the-art heterogeneous catalysts under similar conditions.This work demonstrates that zeoliteencaged metallic catalysts hold great promise to realizeC O 2mediated hydrogen energy cycles in the future that feature fast charge and release kinetics.

Constructing the Support as a Microreactor and Regenerator for Highly Active and In Situ Regenerative Hydrogenation Catalyst

“…Such a hierarchical and porous structure is beneficial for advancing mass transport and encapsulating ultrafine metal species. [17,18] The observed (002) and (101) planes of graphitized C matrix by X-ray diffraction (XRD) spectrum [19] indicates the C atoms in PDAP mainly exist in an sp 2 -hybridized form, which agrees well with the distinct CC and CN peaks observed by X-ray photoelectron spectroscopy (XPS) measurements. [11] N 1s peaks indicate the integration of sp 2 -hybridized N in PDAP mainly comprised of pyridinic (23.4%), graphitic (17.5%), and pyrrolic N (18.6%) (Figure S2, Supporting Information).…”

Heterogeneous catalysts for CO2hydrogenation to formic acid/formate: from nanoscale to single atom

“…Sun and co-workers designed a highly active and stable PdMn alloy catalyst (PdMn 0.6 @S-1) by encapsulating ultra-small PdMn nanoclusters (˂0.7 nm) into silicalite-1 zeolites via an in situ ligand-stabilized hydrothermal approach (Figure 14). 130 The resultant PdMn 0.6 @S-1 catalyst gave a high TOF of 2151 h −1 at 80 °C in aqueous KOH solution (Table 2, entry 49), and could be recycled 5 times with unchanged TOFs thanks to the outstanding confinement effects of silicalite-1 micropores. The superior activity was mainly ascribed to the addition of Mn to form PdMn alloy phases.…”

Enabling storage and utilization of low-carbon electricity: power to formic acid

“…Very recently, the Yu and Yan group has demonstrated the zeolite-encaged Pd-Mn nanocatalysts (PdMnX@S-1) for efficient CO2 hydrogenation to formate. 136 With catalyst PdMn0.6@S-1, the highest formate generation rate of 382 molformate molPd −1 h −1 was achieved at room temperature with a TOF of 466 h −1 . This was around 2-fold higher than that of catalyst Pd@S-1.…”

“…43). Kim and coworkers prepared a biomimetic W IV =O bis-dithiolene complex (136) for gaseous CO2RR to formate at 90 °C in MeCN (Fig. 43).…”