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As a fundamental industrial catalytic process, the semihydrogenation of alkynes presents a challenge in striking a balance between activity and selectivity due to the issue of over‐hydrogenation. Herein, we develop an efficient catalytic system based on single‐atom Pd catalysts supported on boron‐containing amorphous zeolites (Pd/AZ−B), achieving the tradeoff breaking between the activity and selectivity for the selective hydrogenation of alkynes. Advanced characterizations and theoretical density functional theory calculations confirm that the incorporated B atoms in the Pd/AZ−B can not only alter the geometric and electronic properties of Pd atoms by controlling the electron migration from Pd but also mitigate the interaction between alkene and the catalyst supports. This boosts the exceptional catalytic efficacy in the semihydrogenation of phenylacetylene to styrene under mild conditions (298 K, 2 bar H2), achieving a recorded turnover frequency (TOF) value of 24198 h−1 and demonstrating 95 % selectivity to styrene at full conversion of phenylacetylene. By comparison, the heteroatom‐free amorphous zeolite‐anchored Pd nanoparticles and the commercial Lindlar catalyst have styrene selectivities of 73 % and 15 %, respectively, under identical reaction conditions. This work establishes a solid foundation for developing highly active and selective hydrogenation catalysts by controllably optimizing their electronic and steric properties. [ABSTRACT FROM AUTHOR]

Formic acid (FA) dehydrogenation and CO2 hydrogenation to FA/formate represent promising methodologies for the efficient and clean storage and release of hydrogen, forming a CO2‐neutral energy cycle. Here, we report the synthesis of highly dispersed and stable bimetallic Pd‐based nanoparticles, immobilized on self‐pillared silicalite‐1 (SP‐S‐1) zeolite nanosheets using an incipient wetness co‐impregnation technique. Owing to the highly accessible active sites, effective mass transfer, exceptional hydrophilicity, and the synergistic effect of the bimetallic species, the optimized PdCe0.2/SP‐S‐1 catalyst demonstrated unparalleled catalytic performance in both FA dehydrogenation and CO2 hydrogenation to formate. Remarkably, it achieved a hydrogen generation rate of 5974 molH2 molPd−1 h−1 and a formate production rate of 536 molformate molPd−1 h−1 at 50 °C, surpassing most previously reported heterogeneous catalysts under similar conditions. Density functional theory calculations reveal that the interfacial effect between Pd and cerium oxide clusters substantially reduces the activation barriers for both reactions, thereby increasing the catalytic performance. Our research not only showcases a compelling application of zeolite nanosheet‐supported bimetallic nanocatalysts in CO2‐mediated hydrogen storage and release but also contributes valuable insights towards the development of safe, efficient, and sustainable hydrogen technologies. [ABSTRACT FROM AUTHOR]

Bilayer structure with functional overlayer has been commonly adopted to resolve the issue of moisture poisoning in chemiresistors. However, the conventional overlayers always suffer from blocking access of gas molecules to sensing layer due to lacking porosity and deteriorated adsorption capability. Herein, taking advantages of the well-defined porous structure and hydrophobic nature of pure silica zeolite, we assembled an overlayer of Pd-PdO clusters-encapsulated mesoporous silicalite-1 (MFI) zeolite (named M-S-1) on ZnO sensing layer, to prevent moisture poisoning, and enhance gas diffusion and adsorption capabilities. The inherent capability of MFI zeolite to incorporate monodispersed nanometric (ca. 3 nm) Pd-PdO cluster in its void space is of great importance for the NO2 adsorption. The Pd-PdO@M-S-1 overlayer can attain negligible moisture interference to the ZnO layer without significantly altering the gas selectivity and baseline resistance, and enhance gas response. Consequently, the Pd-PdO@M-S-1/ZnO bilayer sensor can ultra-selectively (Snitrogen dioxide/Sinterference gas > 4), and ultra-stably detect trace level of NO2 (9.5 ppb) at low temperature (370 K) under high levels of humidity (90% RH). This work exemplifies a next-generation solution to design bilayer sensors using zeolite overlayer for eliminating the humidity dependence of the gas-sensing properties. [ABSTRACT FROM AUTHOR]