Cu-based nanocatalysts have been widely used for CO2 hydrogenation, but their poor stability is the bottleneck for further industrial applications. A high-performance and long-lived Cu/SiO2 nanocatalyst was synthesized by an ammonia-evaporation method for CO2 hydrogenation. The conversion of CO2 reaches up to 28%, which is close to the equilibrium conversion of CO2 (30%), and the selectivity to methanol is 21.3%, which is much higher than the equilibrium selectivity (6.6%) at 320 °C and 3.0 MPa. Furthermore, after 120 h of evaluation, the conversion can be still maintained at a high value (27%), which is much better than a Cu/SiO2 catalyst prepared by traditional impregnation. The Cu+ species has been demonstrated to be the active component for the activation and conversion of CO2. The higher ratio of Cu+/(Cu0 + Cu+) and interaction between the metal and support deriving from copper phyllosilicate are mainly responsible for the high catalytic activity and excellent stability, respectively.

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A color change: X-ray-induced photochromic species are rare and can be used for detection of X-rays. A highly robust X-ray-sensitive material with the discrete structure of a metal-organic complex has been found to show both soft and hard X-ray-induced photochromism at room temperature. A new ligand-to-ligand electron-transfer mechanism was proposed to elucidate this photochromic phenomenon.

We synthesized monodisperse Pd nanocrystals with exposed (111) and (100) facets through preferentially oriented facet growth technology. We then supported them on α-Al2O3 as catalysts for application in CO oxidative coupling to dimethyl oxalate (DMO) and find, for the first time, that the (111) facets of Pd nanocrystals are active planes for CO oxidative coupling to DMO. This conclusion is based on experiment results, reaction mechanism, and density functional theory calculation. Directed by this shape effect, a high-performance and long-lived nanocatalyst with much lower Pd load for CO oxidative coupling to DMO was successfully prepared by a new wet impregnation–solution chemical reduction method, which can well control the exposure of (111) facets and sizes of Pd nanocrystals.

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Screw-like PdPt nanowires exhibit enhanced performance towards MOR and EGOR attributed to the unique structure and synergetic effect of the catalysts.

The catalytic performances of supported Pd nanoparticles (NPs) are strongly dependent on the support materials for CO oxidative coupling to dimethyl oxalate (DMO). Herein, hierarchical flower-like ZnO microspheres composed of porous nanosheets are employed as a new support material for Pd catalyst, which exhibits excellent catalytic activity for CO oxidative coupling to DMO. The conversion of CO and the selectivity to DMO reach up to 67% and 98% at 130 °C, respectively. Unfortunately, the high activity of Pd/ZnO catalyst gradually deteriorates within 100 h. To resolve the poor stability, we further introduce Mg 2+ ions into ZnO support. It is exciting that the catalytic activity of Mg 2+ -doped ZnO supported Pd nanocatalyst (Pd/Mg-ZnO) can be maintained for at least 100 h without obvious decay. Catalytic stability is greatly improved by the doping of Mg 2+ ions. XRD, UV-DRS and HAADF-STEM-EDS characterizations demonstrate that a small portion of Mg 2+ ions are successfully incorporated into the lattice of ZnO support to form Zn-Mg oxide solid solution. XPS, in situ DR-FTIRS, and H 2 -TPR results reveal that the introduction of Mg 2+ ions into ZnO support leads to a strong metalsupport interaction caused by electron transfer from ZnO substrate to Pd NPs, which can effectively restrain the sintering of the active Pd NPs, retard the growth of Pd NPs, and thus enhance the catalytic stability.

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