An industrial perspective on catalysts for low-temperature CO electrolysis.

Electrochemical conversion of CO to useful products at temperatures below 100 °C is nearing the commercial scale. Pilot units for CO conversion to CO are already being tested. Units to convert CO to formic acid are projected to reach pilot scale in the next year.

CO electrochemical catalytic reduction with a highly active cobalt phthalocyanine.

Molecular catalysts that combine high product selectivity and high current density for CO electrochemical reduction to CO or other chemical feedstocks are urgently needed. While earth-abundant metal-based molecular electrocatalysts with high selectivity for CO to CO conversion are known, they are characterized by current densities that are significantly lower than those obtained with solid-state metal materials. Here, we report that a cobalt phthalocyanine bearing a trimethyl ammonium group appended to the phthalocyanine macrocycle is capable of reducing CO to CO in water with high activity over a broad pH range from 4 to 14.

Molecular electrocatalysts can mediate fast, selective CO reduction in a flow cell.

Practical electrochemical carbon dioxide (CO) conversion requires a catalyst capable of mediating the efficient formation of a single product with high selectivity at high current densities. Solid-state electrocatalysts achieve the CO reduction reaction (CORR) at current densities ≥ 150 milliamperes per square centimeter (mA/cm), but maintaining high selectivities at high current densities and efficiencies remains a challenge. Molecular CORR catalysts can be designed to achieve high selectivities and low overpotentials but only at current densities irrelevant to commercial operation.

Electrolytic CO Reduction in a Flow Cell.

Electrocatalytic CO conversion at near ambient temperatures and pressures offers a potential means of converting waste greenhouse gases into fuels or commodity chemicals (e.g., CO, formic acid, methanol, ethylene, alkanes, and alcohols).

High-Throughput Synthesis of Mixed-Metal Electrocatalysts for CO Reduction.

The utilization of CO as a feedstock requires fundamental breakthroughs in catalyst design. The efficiencies and activities of pure metal electrodes towards the CO reduction reaction are established, but the corresponding data on mixed-metal systems are not as well developed. In this study we show that the near-infrared driven decomposition (NIRDD) of solution-deposited films of metal salts and subsequent electrochemical reduction offers the unique opportunity to form an array of mixed-metal electrocatalyst coatings with excellent control of the metal stoichiometries.

Near-infrared-driven decomposition of metal precursors yields amorphous electrocatalytic films.

Amorphous metal-based films lacking long-range atomic order have found utility in applications ranging from electronics applications to heterogeneous catalysis. Notwithstanding, there is a limited set of fabrication methods available for making amorphous films, particularly in the absence of a conducting substrate. We introduce herein a scalable preparative method for accessing oxidized and reduced phases of amorphous films that involves the efficient decomposition of molecular precursors, including simple metal salts, by exposure to near-infrared (NIR) radiation.

Modulation of charge transport across double-stranded DNA by the site-specific incorporation of copper bis-phenanthroline complexes.

The site-specific incorporation of transition-metal complexes within DNA duplexes, followed by their immobilization on a gold surface, was studied by electrochemistry to characterize their ability to mediate charge. Cyclic voltammetry, square-wave voltammetry, and control experiments were carried out on fully matched and mismatched DNA strands that are mono- or bis-labeled with transition-metal complexes. These experiments are all consistent with the ability of the metal centers to act as a redox probe that is well coupled to the DNA π-stack, allowing DNA-mediated charge transport.