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Metal phthalocyanines (MPcs) have highly conjugated π electron systems and metal atoms acting as active centers, and so exhibit excellent electrocatalytic performance during the oxygen reduction reaction (ORR). However, these complexes also tend to undergo aggregation and exhibit poor electrical conductivity and minimal durability, all of which hinder their large‐scale industrial applications. In the present study, iron phthalocyanine (FePc) is applied to hollow carbon shells (HCSs) to generate an ORR catalyst containing single Fe atoms(HCS‐O‐FePc). The HCSs have numerous N/O‐based surface functional groups that promote the formation of Fe−O bonds with the FePc held in an axial coordination position. These axial Fe−O bonds disrupt the electron symmetry in the plane of the FePc molecules, which facilitate electron transfer. 1100HCS‐O‐FePc exhibits an onset potential of 0.98 V (vs RHE), a half‐wave potential of 0.91 V (vs RHE), an electron transfer number of 3.90, and durability better than that of a 20 % commercial Pt/C catalyst. Electrochemical impedance spectroscopy demonstrates that the ORR process over this material likely proceeds via a rapid 2+2 electron mechanism. This composite displays excellent oxygen reduction properties and is a promising alternative to Pt‐based ORR catalysts. [ABSTRACT FROM AUTHOR]

To develop novel strategies for fabricating metal carbon‐based materials with desirable compositions and structures for catalysis is of great importance. Here we propose for the first time the utilization of metal ionic liquid as a precursor for the synthesis of metal carbon‐based materials through a one‐step pyrolysis route. The method produces the metal dispersed cross‐linked carbon framework with a highly mesoporous structure. Such a Ni/C−N catalyst exhibits outstanding electrocatalytic activity for CO2 reduction reaction, i. e., an excellent CO faradaic efficiency of approximately 94 % at an potential of −0.75 V (versus the reversible hydrogen electrode). The method proposed in this work is simple, convenient, low‐cost, adjustable and versatile for the synthesis of different kinds of M/C−N materials because the structures and properties of metal ionic liquids can be easily designed and tuned by changing the anions and cations. [ABSTRACT FROM AUTHOR]

Highly dispersed catalysts are widely used in industry and academia because of their large surface active sites. However, the predominant short‐range ordered structures in catalysts cannot be revealed by bulk characterization tools. The present study chooses a highly dispersed Fe−SiO2 FTS catalyst as a research object and shows how X‐ray absorption fine structure (XAFS) helps to analyze the chemical information (iron composition, reduction degree, and iron valence) and structural information (coordinating atom and coordination number) of catalyst. The activation process of catalysts are detailedly studied under different atmospheres (CO, H2, or 2H2/CO) by using both ex‐situ and in‐situ XAFS. CO activation behaves most effective during the whole process and finally produces the highest content of active iron species compared with H2 and 2H2/CO activation. The coordination number evolution of nearest Fe−O and Fe−C shells around Fe are put forward to understand the activation process. The present study demonstrates how XAFS elaborately reveals the phase transformations of the highly dispersed Fe−SiO2 FTS catalyst. [ABSTRACT FROM AUTHOR]

The transition metal phosphides have gradually emerged as promising electrocatalysts candidate for oxygen reduction reaction in recent years. As a research hotspot of transition metal phosphides, exploring their mechanism of catalytic activity and the influence of unique morphology is of great significance. In this study, a series of yolk‐shell structure catalysts are fabricated only by pyrolyzing cyclophosphazene microspheres and metal salt without using any other templates, which M2P (M=Fe, Co, Ni) act as the core and N, P co‐doped carbon as the shell. The yolk‐shell structures aim to overcome the inferior conductivity and aggregation problems traditionally existed in application of transition metal phosphides through combination of transition metal phosphides and doped carbon materials. The prepared Fe2P/NPC, Co2P/NPC and Ni2P/NPC catalysts exhibit excellent ORR catalytic activity through the four‐electron pathway, together with large electrochemically active surface area, superior stability and admiring methanol tolerance. What came first: yolk or shell? A series of yolk‐shell structure M2P/NPC catalysts are fabricated by general method without templates for efficient oxygen reduction in alkaline condition. [ABSTRACT FROM AUTHOR]

Abstract: Dimethyl ether steam reforming (DME SR) is a promising route to provide H2 for on‐board H2‐based fuel cells. Herein, we synthesized the La2O3‐modified Cu/SiO2 catalyst with dual copper species of Cu0 and Cu+ for DME SR, which exhibits both the high catalytic performance and long‐term stability. The strong electron donor‐acceptor interaction between the lanthanum and copper species occurs after reduction of the catalysts, which is an essential factor to quantitatively determine the ratio of Cu+/(Cu0+Cu+). The addition of La can improve the dispersion of both metallic Cu and Cu2O on the catalysts, as well. After modulating the ratio of Cu+/(Cu0+Cu+) to ∼0.5 by varying the La loading, we achieved the highest activity and lowest CO selectivity. After the durability tests, the results of TEM, EXAFS, and XPS reveal that the addition of La on the Cu/SiO2 catalysts not only stabilizes the copper species from aggregation, especially for the metallic Cu, but also avoids over‐reduction of the Cu+ species to Cu0. The constant ratio of Cu+/(Cu0+Cu+) on the La‐modified Cu/SiO2 catalyst ensures the high catalytic stability in DME SR. [ABSTRACT FROM AUTHOR]

Abstract: To overcome the limitations of metal–organic frameworks (MOFs) for catalysis (e.g., low catalytic activities resulting from blockage of the active metal centers by organic linkers) is of great importance. Herein, we demonstrate the formation of UiO‐66 nanoparticles with ultrasmall size and linker defects with the aid of SnS2 nanosheets. The UiO‐66 nanoparticles supported by SnS2 nanosheets were found to exhibit excellent catalytic activity for the cycloaddition reaction of CO2 with propylene oxide under solvent‐free and co‐catalyst‐free conditions. Outstandingly, the catalytic activity was 11 times higher than that of the pure UiO‐66 catalyst under optimum conditions. We thus provide a promising route to modify MOF particles thus to promote their catalytic performance. [ABSTRACT FROM AUTHOR]

Abstract: Developing hybrid carbon materials with unique micro/nanostructured and multicomponent features is of great importance in catalysis, energy storage, and energy conversion. Herein, we demonstrate the formation of a novel kind of hybrid carbon material, that is, bimetallic nanoparticles supported by ultrathin (≈5.5 nm) and porous carbon nanosheets, by the pyrolysis of preformed bimetallic metal–organic framework nanosheets. This hybrid carbon nanostructure combines the advantages of highly exposed nanoparticles that are readily accessible to the reactant, multiple active sites such as metal–metal and metal–nitrogen sites and ultrathin carbon layers, and highly efficient electron transport. Owing to these unique features, the bimetallic carbon nanosheets exhibit excellent electrocatalytic performance for the oxygen reduction reaction. [ABSTRACT FROM AUTHOR]

Herein, we report the high activity of CuO-SnO2 catalysts for the catalytic oxidation of CO. In particular, SnCu30 shows the highest activity and a high water resistance. If we compare the XRD, X-ray absorption fine structure, and H2 temperature-programmed reduction results of SnCu30 before and after HNO3 treatment, we find the existence of three kinds of Cu species in the catalyst, that is, highly dispersed CuO, bulk CuO, and Cu incorporated in the SnO2 lattice. The highly dispersed CuO and the surface lattice oxygen species are the active sites for the catalytic oxidation of CO. We used X-ray photoelectron spectroscopy and in situ diffuse reflectance infrared Fourier transform spectroscopy to confirm the existence of Cu+ species on the surface of the CuO-SnO2 catalysts, which can provide the adsorption sites for CO. Our results show that the reaction pathways of the catalytic oxidation of CO over the CuO-SnO2 catalysts follow the Mars-van Krevelen model. [ABSTRACT FROM AUTHOR]

Nitrogen oxides (NO x) contribute much to acid rain, photochemical smog, and the depletion of tropospheric ozone. A novel, small-pore Cu-exchanged chabazite (Cu-CHA) zeolite, Cu-SAPO-44, was first studied for the selective catalytic reduction of NO x with ammonia (NH3-SCR), and exhibits excellent activity and N2 selectivity over the wide temperature window from 200-550 °C. The Cu content in Cu-SAPO-44 plays a significant role in the NH3-SCR reactions. Two kinds of isolated Cu2+ species inside the large cages and in the six-membered rings of the CHA structure were verified as the active sites, which are responsible for the low-temperature and high-temperature activity, respectively. Cu-SAPO-44 is shown to be a promising candidate as a SCR catalyst for deNO x with great potential in after-treatment systems for either mobile or stationary sources. [ABSTRACT FROM AUTHOR]

The Cover shows a novel Cu‐SAPO‐44 zeolite which would be a promising candidate as a selective catalytic reduction (SCR) catalyst for deNOx with great potential in after‐treatment systems for mobile sources.In their Full Paper, Y. Xin et al. report for the first time, insights into the performance and active sites of this novel Cu ion‐exchanged SAPO‐44 zeolite (Cu‐SAPO‐44) in NH3‐SCR. Experimentally derived results demonstrate that Cu‐SAPO‐44 exhibits excellent activity and N2 selectivity over a wide temperature window even after severe hydrothermal aging and that two kinds of isolated Cu2+ species with high thermostability are the active sites. This findings represent a new opportunity for potential industrial applications of Cu‐SAPO‐44 and provide a choice for NOx control in diesel exhausts. More information can be found in the Full Paper by Y. Xin et al. on page 3740 in Issue 24, 2016 (DOI: 10.1002/cctc.201601159). [ABSTRACT FROM AUTHOR]