Adsorption and activation of small molecules on boron nitride catalysts.

Hexagonal boron nitride possesses a unique layered structure, high specific surface area and similar electronic properties as graphene, which makes it not only a promising catalyst support, but also a highly effective metal-free catalyst in the booming field of green chemistry. Reactions involving small molecules (, oxygen, low carbon alkanes, nitrogen and carbon dioxide) have always been a hot topic in catalytic research, especially associated with the adsorption and activation regime of different forms of small molecules on catalysts. In this review, we have investigated the adsorption of different small molecules and the relevant activation mechanisms of four typical chemical bonds (OO, C-H, NN, CO) on hexagonal boron nitride.

Trace CO elimination in H-rich streams with a wide operation temperature window: Co deposited CuO-CeO catalysts.

This work provides a new strategy to eliminate trace CO in H-rich gas in a wide operation temperature window for the application of hydrogen fuel cells. We engineered Co deposited CuO-CeO catalysts with a Co/(Cu + Ce) molar ratio of 1/1 that manages to maintain the CO level at below 100 ppm from 85 to 240 °C in the H-rich reformate stream. CO-PROX and CO methanation reaction respectively occurred in the low and high temperature ranges.

Elucidating the structure, redox properties and active entities of high-temperature thermally aged CuO-CeO catalysts for CO-PROX.

CuOx-CeO2 catalysts with different copper contents are synthesized via a coprecipitation method and thermally treated at 700 °C. Various characterization techniques including X-ray diffraction (XRD) Rietveld refinement, N2 adsorption-desorption isotherms, X-ray photoelectron spectra (XPS), UV-Raman, high-resolution transmission electron microscopy (HRTEM), temperature-programmed reduction (TPR) and in situ diffuse reflectance infrared Fourier transform spectra (DRIFTs) were adopted to investigate the structure/texture properties, oxygen vacancies, Cu-Ce interaction and redox properties of the catalysts. After the thermal treatment, the catalysts exhibited outstanding catalytic properties for the preferential oxidation (PROX) of CO (with the T50% of 62 °C and the widest operation temperature window of 85-140 °C), which provided a new strategy for the design of Cu-Ce based catalysts with high catalytic performance.

Doping effect of transition metals (Zr, Mn, Ti and Ni) on well-shaped CuO/CeO(rods): nano/micro structure and catalytic performance for selective oxidation of CO in excess H.

A series of CuO/CeM(rod) catalysts doped by transition metals were prepared and systematically characterized. The introduction of Mn and Ti plays a significant role in promoting the catalytic performance of the CuO/CeO2(rod) catalyst for the preferential oxidation of CO in H2-rich gas, while the doping with Zr basically maintains the same catalytic activity and Ni leads to a negative influence. Mn and Ti additives remarkably enrich the formation of defect structures and promote copper ion incorporation into the surface of CeM(rod), which greatly facilitates the generation of strong interfacial copper-ceria interaction in CuO/CeMn(rod) and CuO/CeTi(rod).