Sub-3 nm Intermetallic Ordered Pt3In Clusters for Oxygen Reduction Reaction.

Industrial applications of Pt-based oxygen-reduction-reaction (ORR) catalysts are limited by high cost and low stability. Here, facile large-scale synthesis of sub-3-nm ordered Pt3In clusters on commercial carbon black as ORR catalyst that alleviates both these shortcomings is reported. As-prepared Pt3In/C exhibits a mass activity of 0.71 mA mg-1 and a specific area activity of 0.91 mA cm-2 at 0.9 V vs reversible hydrogen electrode, which are 4.1 and 2.7 times the corresponding values of commercial Pt/C catalysts. The as-prepared ordered Pt3In/C catalyst is also remarkably stable with negligible activity and structural decay after 20 000 accelerated electrochemical durability cycles, due to its ordered structure. Density-functional-theory calculations demonstrate that ordered-Pt3In is more energetically favorable for ORR than the commercial Pt/C catalysts because ∆G O is closer to the peak of the volcano plot after ordered incorporation of indium atoms.

Functionalised heterogeneous catalysts for sustainable biomass valorisation.

Efficient transformation of biomass to value-added chemicals and high-energy density fuels is pivotal for a more sustainable economy and carbon-neutral society. In this framework, developing potential cascade chemical processes using functionalised heterogeneous catalysts is essential because of their versatile roles towards viable biomass valorisation. Advances in materials science and catalysis have provided several innovative strategies for the design of new appealing catalytic materials with well-defined structures and special characteristics. Promising catalytic materials that have paved the way for exciting scientific breakthroughs in biomass upgrading are carbon materials, metal-organic frameworks, solid phase ionic liquids, and magnetic iron oxides. These fascinating catalysts offer unique possibilities to accommodate adequate amounts of acid-base and redox functional species, hence enabling various biomass conversion reactions in a one-pot way. This review therefore aims to provide a comprehensive account of the most significant advances in the development of functionalised heterogeneous catalysts for efficient biomass upgrading. In addition, this review highlights important progress ensued in tailoring the immobilisation of desirable functional groups on particular sites of the above-listed materials, while critically discussing the role of consequent properties on cascade reactions as well as on other vital processes within the bio-refinery. Current challenges and future opportunities towards a rational design of novel functionalised heterogeneous catalysts for sustainable biomass valorisation are also emphasized.

Fully dispersed Pt entities on nano-Au dramatically enhance the activity of gold for chemoselective hydrogenation catalysis.

Adding a small amount of fully dispersed Pt entities onto the Au surface in Au/SiO(2) catalyst is found to be an efficient approach to improve the catalytic activity of Au (up to 70-fold) for the hydrogenation of α,ß-unsaturated carbonyl compounds, without alternating its selectivity towards C=O or C=C bond hydrogenation.