Zirconium Carbide Mediates Coke-Resistant Methane Dry Reforming on Nickel-Zirconium Catalysts.

Graphitic deposits anti-segregate into Ni0 nanoparticles to provide restored CH4 adsorption sites and near-surface/dissolved C atoms, which migrate to the Ni0 /ZrO2 interface and induce local Zrx Cy formation. The resulting oxygen-deficient carbidic phase boundary sites assist in the kinetically enhanced CO2 activation toward CO(g). This interface carbide mechanism allows for enhanced spillover of carbon to the ZrO2 support, and represents an alternative catalyst regeneration pathway with respect to the reverse oxygen spillover on Ni-CeZrx Oy catalysts. It is therefore rather likely on supports with limited oxygen storage/exchange kinetics but significant carbothermal reducibility.

A laboratory-based multifunctional near ambient pressure X-ray photoelectron spectroscopy system for electrochemical, catalytic, and cryogenic studies.

A versatile multifunctional laboratory-based near ambient pressure x-ray photoelectron spectroscopy (XPS) instrument is presented. The entire device is highly customized regarding geometry, exchangeable manipulators and sample stages for liquid- and solid-state electrochemistry, cryochemistry, and heterogeneous catalysis. It therefore delivers novel and unique access to a variety of experimental approaches toward a broad choice of functional materials and their specific surface processes. The high-temperature (electro)catalysis manipulator is designed for probing solid state/gas phase interactions for heterogeneous catalysts including solid electrolyzer/fuel cell electrocatalysts at pressures up to 15 mbar and temperatures from room temperature to 1000 °C. The liquid electrochemistry manipulator is specifically designed for in situ spectroscopic investigations of polarized solid/liquid interfaces using aqueous electrolytes and the third one for experiments for ice and ice-like materials at cryogenic temperatures to approximately -190 °C. The flexible and modular combination of these setups provides the opportunity to address a broad spectrum of in situ and operando XPS experiments on a laboratory-based system, circumventing the limited accessibility of experiments at synchrotron facilities.

Who Does the Job? How Copper Can Replace Noble Metals in Sustainable Catalysis by the Formation of Copper-Mixed Oxide Interfaces.

Following the need for an innovative catalyst and material design in catalysis, we provide a comparative approach using pure and Pd-doped LaCu x Mn1-x O3 (x = 0.3 and 0.5) perovskite catalysts to elucidate the beneficial role of the Cu/perovskite and the promoting effect of Cu y Pd x /perovskite interfaces developing in situ under model NO + CO reaction conditions. The observed bifunctional synergism in terms of activity and N2 selectivity is essentially attributed to an oxygen-deficient perovskite interface, which provides efficient NO activation sites in contact with in situ exsolved surface-bound monometallic Cu and bimetallic CuPd nanoparticles. The latter promotes the decomposition of the intermediate N2O at low temperatures, enhancing the selectivity toward N2. We show that the intelligent Cu/perovskite interfacial design is the prerequisite to effectively replace noble metals by catalytically equally potent metal-mixed-oxide interfaces. We have provided the proof of principle for the NO + CO test reaction but anticipate the extension to a universal concept applicable to similar materials and reactions.