No abstract

The   electrocatalytic carbon dioxide reduction reaction (CO 2 RR) addresses the need for storage of renewable energy in valuable carbon-based fuels and feedstocks, yet challenges remain in the improvement of electrosynthesis pathways for highly selective hydrocarbon production. To improve catalysis further, it is of increasing interest to lever synergies between heterogeneous and homogeneous approaches. Molecules adjacent to the active site provide additional binding interactions that may tune the stability of intermediates, improving catalytic performance by increasing Faradaic efficiency (product selectivity), as well as decreasing overpotential. We offer a forward-looking perspective on molecularly enhanced heterogeneous catalysis for CO 2 RR. We discuss four categories of molecularly enhanced strategies: molecular-additive-modified heterogeneous catalysts, immobilized organometallic complex catalysts, reticular catalysts and metal-free polymer catalysts. We introduce presentday challenges in molecular strategies and describe a vision for CO 2 RR electrocatalysis towards multi-carbon products. These strategies provide potential avenues to address the challenges of catalyst activity, selectivity and stability in the further development of CO 2 RR.

The activity of several group 4 metal alkoxide complexes supported by ferrocene-based ligands was controlled using redox reagents during the ring-opening polymerization of l-lactide and ε-caprolactone. Switching in situ between the oxidized and reduced forms of a metal complex resulted in a change in the corresponding rate of polymerization. Opposite behavior was observed for each monomer used. One-pot copolymerization of the two monomers to give block copolymers was also achieved.

CO 2 electroreduction to chemical feedstocks has suffered from CO 2 reactant loss and a severe energy consumption/production penalty associated with carbonate formation. We divided the process into two cascading steps-CO 2 reduction to CO in a solid-oxide electrolysis cell (SOEC) and CO reduction to multi-carbon products in a membrane electrode assembly (MEA) electrolyser. In the full SOEC-MEA cascade approach, we achieve CO 2 -to-C 2 H 4 with no loss of CO 2 to carbonate and a ~48% reduction in energy intensity compared with the direct route.