The NH4+ generation rate over the as-prepared ternary metal sulfide catalysts is linearly related to the sulfur vacancy concentration, confirming that the photocatalytic reduction capacity of N2 over ternary metal sulfides is highly dependent on the amount of sulfur vacancies.

Operando and kinetic studies of lean-burn methane combustion were preformed on a Pd­(3.3 wt %)/γ-Al2O3 catalyst in a low temperature range of 473–673 K. The reaction order with respect to oxygen decreased with temperature, and the order with respect to methane remained constant. The working catalyst is characterized using operando Raman spectroscopy and in situ diffuse reflectance infrared Fourier transform spectroscopy of CO adsorption (DRIFTS), and the Pd chemical states were measured with X-ray photoelectron spectroscopy (XPS). Partial oxidation of Pd atoms during reaction was identified by Raman and XPS spectroscopies. In particular, the DRIFT spectra revealed that ∼45% of Pd atoms at the top layers were transferred into PdO x species above 523 K. The reaction was assumed to occur primarily on the metallic Pd sites below 673 K, proceeding through the Langmuir–Hinshelwood mechanism, and Pd oxide may affect the adsorption and activation of reactants.

Higher alcohol synthesis (HAS) directly from syngas is one of the most promising approaches for utilizing nonoil resources cleanly and efficiently. A series of bimetallic CoCu catalysts with different Co/Cu ratios were prepared using a SiO2 support. The structure of Cu modified Co catalysts was characterized using HRTEM, in/ex situ X‐ray diffraction, and temperature‐programmed reduction. It was evidenced that nanoscale metal particles were formed and the reduction of Co oxide at above 673 K. Meanwhile, the interaction between Co and Cu on the surface was assumed to be responsible for the enhanced selectivity to HAS. The intrinsic kinetics for this reaction was performed over a CoCu/SiO2 catalyst under realistic conditions. The kinetic parameters, including apparent activation energies and reaction orders, were calculated through power‐law models. With the combination of chain growth probability and kinetics, the effect of temperatures on the reaction mechanism and the Cu promotional effects on Co catalysts were elaborated. © 2014 American Institute of Chemical Engineers AIChE J, 60: 1797–1809, 2014