Carbon nanotubes (CNTs) have well-defined hollow interiors and exhibit unusual mechanical and thermal stability as well as electron conductivity. This opens intriguing possibilities to introduce other matter into the cavities, which may lead to nanocomposite materials with interesting properties or behaviour different from the bulk. Here, we report a striking enhancement of the catalytic activity of Rh particles confined inside nanotubes for the conversion of CO and H2 to ethanol. The overall formation rate of ethanol (30.0 mol mol(-1)Rh h(-1)) inside the nanotubes exceeds that on the outside of the nanotubes by more than an order of magnitude, although the latter is much more accessible. Such an effect with synergetic confinement has not been observed before in catalysis involving CNTs. We believe that our discovery may be of a quite general nature and could apply to many other processes. It is anticipated that this will motivate theoretical and experimental studies to further the fundamental understanding of the host-guest interaction within carbon and other nanotube systems.

Utilization of nonprecious transition metals for high alcohols synthesis is of a great importance in heterogeneous catalysis. We synthesized successfully cobalt metal-carbide (Co− Co 2 C) catalysts, which present remarkable activity and selectivity for high alpha-alcohols via the Fischer−Tropsch reaction. The formation of the stable cobalt carbide and the Co−Co 2 C interface are found to be essential for the observed reactivity. Density functional theory calculations show that Co 2 C is highly efficient for CO nondissociative adsorption, behaving as noble-metal-like, whereas the Co metal is highly active for CO dissociative adsorption and the subsequent carbon-chain growth. The interface between the cobalt metal and its carbide phase, as well as the dual sites available at the interface for facile CO insertion to hydrocarbon, could be used to rationalize the design of the nonprecious transition metal catalysts for the oxygenates in syngas conversion.

A series of ionic liquid (IL), zinc halide (ZnX 2 ), and triphenylphosphine (PPh 3 ) integrated porous organic polymers (POPs) featuring multifunctional sites were afforded through solvothermal synthesis for cyclic carbonate synthesis which utilizes epoxides and carbon dioxide (CO 2 ). Owing to the cooperative effect of ionic liquid and homogeneously distributed Zn-PPh 3 specie, which is probably strengthened by the confined microporous structure and flexible frameworks, these POPs catalysts exhibited high CO 2 capture and conversion performance and provided the highest activity (initial turnover frequencies up to 5200 h −1 ) of heterogeneous catalysts reported to date within the context of cyclic carbonate formation. Even more surprising, very favorable turnover numbers (TONs) of 2120 and 720 were attained at 40 and 25 °C, respectively. The effect of reaction parameters (reaction time, temperature, CO 2 pressure) on the catalytic performance as well as other epoxide substrates were also investigated in detail. Furthermore, the catalyst can be easily recovered and reused five times without a significant loss of activity. These ionic liquid and Zn-PPh 3 constructed porous polymers may provide an industrial opportunity for cyclic carbonate products.