We present a Li-intercalated-CeO2 catalyst that exhibits outstanding activity for ammonia synthesis. The incorporation of Li significantly reduces the activation energy and suppresses hydrogen poisoning of the Ru co-catalysts. As a result, the lithium intercalation enables the catalyst to achieve ammonia production from N2 and H2 at substantially lower operating temperatures.

Direct non-oxidative dehydrogenation of alkanes produces useful carbon feedstocks and hydrogen fuel. However, breaking the C–H bonds in alkanes typically requires high temperature, stoichiometric oxidants or high-energy ultraviolet light; processes that operate under milder conditions are attractive but tend to have poor efficiency. Here we report Pt/black TiO 2 photocatalysts in which Pt species are close to each other but not directly bonded, exhibiting high performance for alkane dehydrogenation in visible to near-infrared light at room temperature. For cyclohexane dehydrogenation, the turnover number for H 2 production exceeded 100,000 without any deactivation over 80 reaction cycles, far beyond thermal reactions. For methane, 8.2% conversion was achieved with 65% selectivity to propane, rather than the more common ethane. We propose that methane undergoes intramolecular dehydrogenation to produce a methylene intermediate. For C2+ alkanes, fast dehydrogenation (up to 1,440 µmol g −1 h −1 ) to the corresponding olefins was realized. Distinct from isolated Pt + monomers, the collections of Pt + monomers give better photocatalytic activity and selectivity.

An efficient and robust ammonia synthesis is achieved over lithiated MoO 2− x nanosheets with Fe loading. Li + insertion results in the downshift of the d -band center, which markedly decreases the affinity to NH x ( x = 0–2) and apparent activation energy simultaneously.

Achieving efficient photocatalytic ammonia synthesis under mild conditions provides a sustainable approach for producing nitrogen-containing resources. The current challenge is to find ideal photocatalysts with strong N-2 activation capacity and superior interfacial charge transfer. Herein, we report that efficient photocatalytic ammonia synthesis can be achieved across the entire visible light region over Ti-doped defective ZnO1-x with Ru cocatalyst loading. Due to the presence of local electrostatic fields and unique surface structures, the Ti atoms doped on the nonpolar (100) facets of ZnO1-x trigger the most strong activation of N-2 with excellent electron back-donation power, resulting in an unprecedented elongation of N equivalent to N bonds, from the original 1.117 to 1.328 angstrom, as well as one-electron reduction of N-2 to N-2(-). The supported Ru cocatalyst enables the upward band bending of ZnO and the formation of interfacial Schottky contacts, simultaneously enhancing the reduction potential of photogenerated electrons and minimizing electron-hole recombination, which further promotes the efficiency of ammonia synthesis.

The first observation of surface metallization of TiO 2− x induced by fluoride ions is presented. The emerging metallic states are contributed by the 3d orbital of surface Ti and the 2p orbital of surface bridging F, which are intrinsically originated from the strong electron repulsion between F − and adjacent Ti 3+ . The metalized TiO 2− x with reduced work function and downward band bending possesses high electron-donating power to supported Ru species via atomic-scale ohmic contacts, exhibiting unprecedented photocatalytic performances for ammonia synthesis across the entire solar spectrum region (200–1550 nm) at room temperature. Mechanism and kinetic analysis revealed that the loaded Ru could behave as efficient electron sinks to accumulate photogenerated electrons and that the metallic surface markedly enhanced the dissociation of H 2 and N 2 by the hot electrons generated by the visible or even infrared light irradiation.

Electronic control of Fe nanoparticles can provide a great opportunity to manipulate their magnetic properties and improve their catalytic activity. Herein, superparamagnetic Fe nanoclusters with Pt2+ doping are synthesized on a variety of semiconductor nitrides, oxides and silicon. Compared to the intrinsic Fe nanoclusters, the as-synthesized Pt-doped Fe nanoclusters exhibit ultrasmall size with a very low saturation magnetization (2.0 emu g(-1)) and high electron delocalization. The incorporation of Pt2+ dopants also leads to the successful formation of a large Schottky barrier at the iron/semiconductor interface and renders semiconductor a powerful electron donor for Fe active sites under photo irradiation. Photoluminescence spectroscopy and transient photocurrent responses indicate that the formed Schottky barrier can significantly promote the separation of photogenerated charge carriers. Mott-Schottky photocatalysts with enhanced back donation ability provides an efficient pathway to promote N N bond cleavage and produce ammonia with H-2 at room temperature by visible light.

The visible-light photocatalytic performance of the heterostructured g-C3N4/Ag/Bi3.64Mo0.36O6.55 nano spheres was investigated. As electron sinks, Ag nanoparticles (NPs) were photodeposited as the interlayer between g-C3N4 and the surface of Bi3.64Mo0.36O6.55 nanospheres to increase visible-light absorption via the surface plasmon resonance. The g-C3N4/Ag/Bi3.64Mo0.36O6.55 nanospheres displayed efficiently photo catalytic performance, higher than that of pure g-C3N4/Ag/Bi3.64Mo0.36O6.55, Ag/Bi3.64Mo0.36O6.55, and g-C3N4/Bi3.64Mo0.36O6.55 samples. The photocatalytic efficiency enhancement of g-C3N4/Ag/Bi3.64Mo0.36O6.55 photocatalyst could be ascribed to the efficient separation of electron-hole pairs through the heterostruncture composed of Bi3.64Mo0.36O6.55, Ag and g-C3N4. In addition, the quenching effects of different scavengers revealed that the reactive h(+) and O-2(center dot-) play the major role in the Rh B decolorization. (C) 2016 Elsevier B.V. All rights reserved.

Heterostructured RGO/Bi3.64Mo0.36O6.55 nanospheres with different weight fractions of RGO were synthesized via a simple and practical low-temperature solution-phase route by using Bi3.64Mo0.36O6.55 nanospheres as substrate materials. The as-prepared RGO/Bi3.64Mo0.36O6.55 nanoheterostructure included RGO nanoparticles assembling on the surface of Bi3.64Mo0.36O6.55 nanospheres. Comparing with pure Bi3.64Mo0.36O6.55, RGO/Bi3.64Mo0.36O6.55 hybrid photocatalysts exhibited enhanced photocatalytic activities under visible light irradiation in the decomposition of rhodamine B (RhB) solution, and the RGO/Bi3.64Mo0.36O6.55 photocatalyst with 3 wt% of RGO exhibited the highest photocatalytic activity. The enhanced performance is believed to be induced by the high specific surface area, the strong visible-light absorption originating from the sensitization of RGO, and the high efficient separation of photogenerated electron-hole pairs through RGO/Bi3.64Mo0.36O6.55 heterostructure. (C) 2015 Elsevier B.V. All rights reserved.