Designing effective electrocatalysts for the carbon dioxide reduction reaction (CO2 RR) is an appealing approach to tackling the challenges posed by rising CO2 levels and realizing a closed carbon cycle. However, fundamental understanding of the complicated CO2 RR mechanism in CO2 electrocatalysis is still lacking because model systems are limited. We have designed a model nickel single-atom catalyst (Ni SAC) with a uniform structure and well-defined Ni-N4 moiety on a conductive carbon support with which to explore the electrochemical CO2 RR. Operando X-ray absorption near-edge structure spectroscopy, Raman spectroscopy, and near-ambient X-ray photoelectron spectroscopy, revealed that Ni+ in the Ni SAC was highly active for CO2 activation, and functioned as an authentic catalytically active site for the CO2 RR. Furthermore, through combination with a kinetics study, the rate-determining step of the CO2 RR was determined to be *CO2 - +H+ →*COOH. This study tackles the four challenges faced by the CO2 RR; namely, activity, selectivity, stability, and dynamics.

https://onlinelibrary.wiley.com/doi/epdf/10.1002/anie.201915193

Elucidating the Electrocatalytic CO 2 Reduction Reaction over a Model Single-Atom Nickel Catalyst

A novel metallophthalocyanine derivative, cobalt tetra (2,4-dichloro-1,3,5-triazine) aminophthalocyanine (Co-TDTAPc), was prepared and immobilized on cellulosic fiber by covalent bond to obtain a supported oxidation catalyst (Co-TDTAPc-F). Co-TDTAPc-F/H2O2 system based on phase-transfer catalytic oxidation for decomposing dyes, including acid, reactive, and direct dyes, has been investigated thoroughly. Compared to traditional adsorption technologies and advanced oxidation processes (AOPs) for dye treatment, Co-TDTAPc-F/H2O2 combines the advantages of both and is more efficient and more effective. Azo dyes such as C. I. Acid Red 1 (AR1) can be quickly adsorbed onto/into the fiber from aqueous solution and decomposed in situ simultaneously in the presence of Co-TDTAPc-F and H2O2. It has been found that the reaction process is not affected by the visible light. Furthermore, it turns the negative effect of NaCl normally observed in homogeneous catalysis into positive one. The catalytic reaction can proceed a...

Highly efficient decomposition of organic dyes by aqueous-fiber phase transfer and in situ catalytic oxidation using fiber-supported cobalt phthalocyanine.

Metallophthalocyanine functionalized silicas: catalysts for the selective oxidation of aromatic compounds

Electrocatalysis of asulam on cobalt phthalocyanine modified multi-walled carbon nanotubes immobilized on a basal plane pyrolytic graphite electrode

In this work a selection of octasubstituted phthalocyaninato zinc complexes were synthesized and their photochemistry studied. The substituents included cholesterol (3a), estrone (3b), naphthol (3c) and phenoxy groups substituted with CH3 (3d), C(CH3)3 (at two positions, 3e), C(CH3)3 (3f), NO2 (3g), NH2 (3h), COH (3i), COOH (3j), and H (3k). In general, complexes containing electron-donating groups attached to the phenoxy ring (e.g. 3e and 3f) were found to be photochemically unstable with photobleaching quantum yields of the order of 10-3. In the presence of electron-withdrawing groups (3g, 3i, and 3j) the photobleaching quantum yields were of the order of 10-6 to 10-5. Singlet oxygen quantum yields (ΦΔ) ranged from 0.01 to 0.73. The lowest ΦΔ was observed for the highly aggregated complex 3c. All the complexes showed aggregation at high concentrations. Electrochemical reduction using a thin-layer spectroelectrochemistry cell showed that the complexes become more monomeric following reduction.

J.A. Parker

Papers

Synthesis and structural studies of metal(II) 4,9,16,23-phthalocyanine tetraamines