Selective Reduction of CO2 to a Formate Equivalent with Heterobimetallic Gold‐ ‐ ‐Copper Hydride Complexes

A series of heterobimetallic complexes containing three‐center, two‐electron Au−H−Cu bonds have been prepared from addition of a parent gold hydride to a bent d¹⁰ copper(I) fragment. These highly unusual heterobimetallic complexes represent a missing link in the widely investigated series of neutral and cationic coinage metal hydride complexes containing Cu−H−Cu and M−H−M⁺ moieties (M=Cu, Ag). The well‐defined heterobimetallic hydride complexes act as precatalysts for the conversion of CO₂ into HCO₂Bpin with HBpin as the reductant. The selectivity of the heterobimetallic complexes for the catalytic production of a formate equivalent surpasses that of the parent monomeric Group 11 complexes.     

An Hetero‐Epitaxially Grown Zeolite Membrane

The secondary growth methodology to form zeolite membranes has stringent requirements for homogeneous epitaxial intergrowth of the seed layer and limits the number of accessible high‐quality zeolite membranes. Despite previous reports on hetero‐epitaxial growth, high‐performance zeolite membranes have yet to be reported using this approach. Here, the successful hetero‐epitaxial growth of highly siliceous ZSM‐58 (DDR‐type zeolite) films from a SSZ‐13 (CHA‐type zeolite) seed layer is reported. The resulting membranes show excellent CO₂ perm‐selectivities, having maximum CO₂ /N₂ and CO₂ /CH₄ separation factors (SFs) as high as about 17 and 279, respectively, at 30 °C. Furthermore, the hybrid membrane maintains the CO₂ perm‐selectivity in the presence of water vapor (the third main component in both cases), that is, CO₂ /N₂ SF of about 14 and CO₂ /CH₄ SF of about 78, respectively, at 50 °C (a representative temperature of both CO₂‐containing streams).     

Aqueous CO2 Reduction with High Efficiency Using α‐Co(OH)2‐Supported Atomic Ir Electrocatalysts

Electrochemical reduction of CO₂ into energy‐dense chemical feedstock and fuels provides an attractive pathway to sustainable energy storage and artificial carbon cycle. Herein, we report the first work to use atomic Ir electrocatalyst for CO₂ reduction. By using α‐Co(OH)₂ as the support, the faradaic efficiency of CO could reach 97.6 % with a turnover frequency (TOF) of 38290 h^?1 in aqueous electrolyte, which is the highest TOF up to date. The electrochemical active area is 23.4‐times higher than Ir nanoparticles (2 nm), which is highly conductive and favors electron transfer from CO₂ to its radical anion (CO₂^.?). Moreover, the more efficient stabilization of CO₂^.? intermediate and easy charge transfer makes the atomic Ir electrocatalyst facilitate CO production. Hence, α‐Co(OH)₂‐supported atomic Ir electrocatalysts show enhanced CO₂ activity and stability.     

CO2‐Activated Reversible Transition between Polymersomes and Micelles with AIE Fluorescence

Fluorescent polymersomes with both aggregation‐induced emission (AIE) and CO₂‐responsive properties were developed from amphiphilic block copolymer PEG‐b‐P(DEAEMA‐co‐TPEMA) in which the hydrophobic block was a copolymer made of tetraphenylethene functionalized methacrylate (TPEMA) and 2‐(diethylamino)ethyl methacrylate (DEAEMA) with unspecified sequence arrangement. Four block copolymers with different DEAEMA/TPEMA and hydrophilic/hydrophobic ratios were synthesized, and bright AIE polymersomes were prepared by nanoprecipitation in THF/water and dioxane/water systems. Polymersomes of PEG₄₅‐b‐P(DEAEMA₃₆‐co‐TPEMA₆) were chosen to study the CO₂‐responsive property. Upon CO₂ bubbling vesicles transformed to small spherical micelles, and upon Ar bubbling micelles returned to vesicles with the presence of a few intermediate morphologies. These polymersomes might have promising applications as sensors, nanoreactors, or controlled release systems.