Modulation of p-Block Electron Orbits in Metal-Organic Frameworks for CO2 Capture and Electrochemical Reduction

Developing catalysts with excellent CO2 capture capability and electrochemical CO2 reduction reaction (CO2RR) at a wide potential range simultaneously is significant but remains a formidable challenge. Here, two novel InMg defective trinuclear cluster-based MOFs (SNNU-41 and SNNU-42) with abundant p-block unsaturated coordinated sites were reported and exhibited good CO2 capture and CO2RR performance simultaneously. Due to the suitable micropores, SNNU-41 showed higher CO2 capture ability at different adsorption pressure conditions. On account of the rigid framework and the closer p band center to Fermi level, SNNU-42 accelerated the conversion of CO2 molecule to C1 efficiency. Notably, via adjusting the ratio of p-block metal (In) in the SNNU-42 framework, the performance of the CO2RR was promoted drastically. SNNU-42 with the InMg (1:1.8) mixed cluster delivered an excellent Faradaic efficiency of 91.3% for C1 products and high selectivity of 72.0% for HCOOH at -2.5 V (vs Ag/Ag+) with a total current density of 77.2 mA cm-2. This work provides a possibility for efficient CO2 capture and CO2RR electrocatalysts through the modulation of electronic structures and composition in MOFs.

Some new azobenzene liquid crystals involving chalcone and ester linkages

New azobenzene derivatives containing chalcone and ester linkages showed photo-responsive behaviours and alkoxy chain and terminal group effects on their mesomorphic properties.

Synthesis, spectral and thermal characterization of polyester derived from 1,1-bis(4-hydroxyphenyl)cyclohexane

A series of polyesters with pendant cyclohexane ring as a cardo group were synthesized by reacting 1,1-bis(4-hydroxyphenyl)cylcohexane (bisphenol-Z (BPZ)) with diacid chlorides. The molecular structures of the monomer and polymers were confirmed by spectral analyses. Thermal properties were studied using thermogravimetric analysis and differential scanning calorimetry. The thermogravimetric data revealed that the polymers are stable up to 190°C and start to degrade thereafter. The thermal stability initially increases with increase in spacer length and then decreases due to negative effects of the spacer. In the present study, Arrhenius, Broido and Horowitz–Metzger models have been used to calculate the degradation kinetic parameters.