Multifunctional Pd/MOFs@MOFs Confined Core‐Shell Catalysts with Wrinkled Surface for Selective Catalysis

Abstract

Process intensification, targeting the maximization of spatial-temporal productivity utilizing minimum energy and resources has always been the constant trends especially in chemical industry. In this regard, tandem reactions that are able to perform a multi-step reaction in a single pot by eliminating costly separation steps have been viewed as a typical paradigm. However, a spatial isolation of varied active sites with a controlled manner in a single catalyst to avoid deactivation and work synergistically is a challenging problem yet sometimes being overlooked. In this work, a spatial base-metal core-shell structured catalyst with wrinkled surface was successfully fabricated by a direct homoepitaxial growth method in an acid/water system, which exhibited increased hydrophobicity, exposure of active sites and significantly improved product selectivity towards one-pot Knoevenagel condensation-hydrogenation tandem reaction compared with the uncoated catalyst. Meanwhile, the catalytic performance was largely retained and the structural stability was maintained even after successive 8 cycles, which shows great promise for industrial applications.

Simulation and Analysis of Thermal Stress and Sintering Warpage of Planar Solid Oxide Fuel Cells

“…The developed model is validated by comparing the predictions with the data obtained from other literature (20), in which the thermal expansion coefficient of the cathode is fixed as a constant value of 10×10 -6 K -1 , while the one for the anode is varied. The predicted thermal stress is shown in Table . The relative error is employed for this comparison:…”

Pd–IL@H-UiO-66-NH2: a hollow multi-functional hierarchical composite for tandem catalysis

“…Core-shell materials have been explored in the context of tandem catalysis because they possess inner and outer parts with different compositions in which two or more wellseparated catalytic sites can be inserted. [22][23][24][25][26][27] However, the large distances that exist between different active sites in pristine core-shell structures can significantly limit the efficiency of mass transfer and the accessibility of active sites. 28,29 Materials comprised of hollow structures with abundant internal voids and tunable outer shells are a special class of core-shell structures.…”

Pd Clusters on Schiff Base–Imidazole-Functionalized MOFs for Highly Efficient Catalytic Suzuki Coupling Reactions

“…Metal−organic frameworks (MOFs) are a fascinating family of porous crystalline materials assembled with inorganic metal nodes and organic linkers, possessing large internal surface areas, well-defined structures, and tunable chemical properties ( Lee et al, 2009 ; Li et al, 2012 ; Furukawa et al, 2013 ). These features confer their popular applications in heterogeneous catalysis, particularly when they are used as support for noble metal (e.g., Pd, Au, Ru, and Pt) nanoparticles (MNPs) ( He et al, 2018 ; Han et al, 2019 ; Chen et al, 2021 ; Khan et al, 2021 ). On the one hand, the permanent porosity and uniform channels of MOFs make them particularly suitable for the efficient immobilization of MNPs that protect the MNPs from sintering and aggregation without inhibiting the diffusion of the reactants and products.…”