Cu Based Dilute Alloys for Tuning the C Selectivity of Electrochemical CO Reduction.

Electrochemical CO reduction is a promising technology for replacing fossil fuel feedstocks in the chemical industry but further improvements in catalyst selectivity need to be made. So far, only copper-based catalysts have shown efficient conversion of CO into the desired multi-carbon (C) products. This work explores Cu-based dilute alloys to systematically tune the energy landscape of CO electrolysis toward C products.

Evaluating the stability and activity of dilute Cu-based alloys for electrochemical CO reduction.

Cu-based catalysts currently offer the most promising route to actively and selectively produce value-added chemicals via electrochemical reduction of CO (eCOR); yet further improvements are required for their wide-scale deployment in carbon mitigation efforts. Here, we systematically investigate a family of dilute Cu-based alloys to explore their viability as active and selective catalysts for eCOR through a combined theoretical-experimental approach. Using a quantum-classical modeling approach that accounts for dynamic solvation effects, we assess the stability and activity of model single-atom catalysts under eCOR conditions.

CO reduction on pure Cu produces only H after subsurface O is depleted: Theory and experiment.

We elucidate the role of subsurface oxygen on the production of C products from CO reduction over Cu electrocatalysts using the newly developed grand canonical potential kinetics density functional theory method, which predicts that the rate of C production on pure Cu with no O is ∼500 times slower than H evolution. In contrast, starting with CuO, the rate of C production is >5,000 times faster than pure Cu(111) and comparable to H production. To validate these predictions experimentally, we combined time-dependent product detection with multiple characterization techniques to show that ethylene production decreases substantially with time and that a sufficiently prolonged reaction time (up to 20 h) leads only to H evolution with ethylene production ∼1,000 times slower, in agreement with theory.

Electrocatalysis at Organic-Metal Interfaces: Identification of Structure-Reactivity Relationships for CO Reduction at Modified Cu Surfaces.

The limited selectivity of existing CO reduction catalysts and rising levels of CO in the atmosphere necessitate the identification of specific structure-reactivity relationships to inform catalyst development. Herein, we develop a predictive framework to tune the selectivity of CO reduction on Cu by examining a series of polymeric and molecular modifiers. We find that protic species enhance selectivity for H, hydrophilic species enhance formic acid formation, and cationic hydrophobic species enhance CO selectivity.

Stereoelectronic Effects on the Binding of Neutral Lewis Bases to CdSe Nanocrystals.

Using P nuclear magnetic resonance (NMR) spectroscopy, we monitor the competition between tri- n-butylphosphine (BuP) and various amine and phosphine ligands for the surface of chloride terminated CdSe nanocrystals. Distinct P NMR signals for free and bound phosphine ligands allow the surface ligand coverage to be measured in phosphine solution. Ligands with a small steric profile achieve higher surface coverages (BuP = 0.

Bimetallic coordination insertion polymerization of unprotected polar monomers: copolymerization of amino olefins and ethylene by dinickel bisphenoxyiminato catalysts.

Dinickel bisphenoxyiminato complexes based on highly substituted p- and m-terphenyl backbones were synthesized, and the corresponding atropisomers were isolated. In the presence of a phosphine scavenger, Ni(COD)2, the phosphine-ligated syn-dinickel complexes copolymerized α-olefins and ethylene in the presence of amines to afford 0.2-1.