Doped Ceria Catalyst System: Catalyzing Carbon Monoxide Transformation (A-Review)

As ceria chemistry broadens, it is needed to generalize the behavior of ceria surfaces towards molecules for carrying out a reaction. The endowing capacity of mobile oxygen due to rapid redox switching between Ce+4/Ce+3 is a key point for ceria containing surfaces. Herein we have presented a review which is broadly divided into two parts. First part focuses on surface property as how electronic structure, vacancy and surface energy would be modified after interaction of ceria with dopant (noble metal, metal of variable oxidation state, higher valent metal and lower valent metal). The second part focuses on catalysis as how the doped ceria surface influences the carbon monoxide transformations (CO oxidation, CO and H2O reaction, CO and NO reaction, CO and H2 reaction). This through study will be helpful to predict the ceria surface for a designed reaction.

A Novel Cobalt Metallopolymer with Redox-Matched Conjugated Organic Backbone via Electropolymerization of a Readily Available N4 Cobalt Complex

Fast and reversible cobalt-centered redox reactions in metallopolymers are the key to using these materials in energy storage, electrocatalytic, and sensing applications. Metal-centered electrochemical activity can be enhanced via redox matching of the conjugated organic backbone and cobalt centers. In this study, we present a novel approach to redox matching via modification of the cobalt coordination site: a conductive electrochemically active polymer was electro-synthesized from [Co(Amben)] complex (Amben = N,N′-bis(o-aminobenzylidene)ethylenediamine) for the first time. The poly-[Co(Amben)] films were investigated by cyclic voltammetry, electrochemical quartz crystal microbalance (EQCM), in situ UV‑vis-NIR spectroelectrochemistry, and in situ conductance measurements between −0.9 and 1.3 V vs. Ag/Ag+. The polymer displayed multistep redox processes involving reversible transfer of the total of 1.25 electrons per repeat unit. The findings indicate consecutive formation of three redox states during reversible electrochemical oxidation of the polymer film, which were identified as benzidine radical cations, Co(III) ions, and benzidine di-cations. The Co(II)/Co(III) redox switching is retained in the thick polymer films because it occurs at potentials of high polymer conductivity due to the optimum redox matching of the Co(II)/Co(III) redox pair with the organic conjugated backbone. It makes poly-[Co(Amben)] suitable for various practical applications based on cobalt-mediated redox reactions.

Synthesis of Bis{meso-Tetrakis(4-N-alkylpyridiniumyl)porphyrinato}cerium and Its Redox Switching Behavior

A novel double-decker porphyrin complex, bis{meso-tetrakis(4-N-alkylpyridiniumyl)porphyrinato}cerium, was prepared. Electrochemical measurements revealed that this complex exhibited reversible redox waves corresponding to a 1e– redox reaction of the cerium center. Treating the complex alternately with an oxidant and a reductant resulted in the reversible redox switching between the oxidized and reduced states in an organic solvent.

Fast Synthesis and Redox Switching of Di- and Tetra-substituted Bisthioxanthylidene Overcrowded Alkenes

A rapid and efficient method for the synthesis of overcrowded alkenes using (trimethylsilyl)diazomethane provides a range of substituted bisthioxanthylidenes. We show large conformational redox switching from folded to orthogonal states,...

pH-Responsive colorimetric, emission and redox switches based on Ru(ii)–terpyridine complexes

Ru(ii)–Terpyridine complexes exhibit pH-responsive colorimetric, emission and redox switching behaviours.

Conquering residual light absorption in the transmissive states of organic electrochromic materials

Using a feedback loop between computational modeling probing electronic transitions and experimental work, the colors, transmissivity, and redox switching properties of a family of anodically coloring electrochromic molecules are reviewed.