Biochemical and artificial pathways for the reduction of carbon dioxide, nitrite and the competing proton reduction: effect of 2^ndsphere interactions in catalysis

Abstract

Reduction of oxides and oxoanions of carbon and nitrogen are of great contemporary importance as they are crucial for a sustainable environment.

Shaping the Electrocatalytic Performance of Metal Complexes for CO2 Reduction

“…This being so, primarily because of their involvement in natural systems performing such processes. Metalloporphyrin‐containing enzymes are for instance implicated in the reduction of oxygen, nitrite, sulfite, and the reductive activation of oxygen, among others [4–7] . Although metalloporphyrins are not involved at the catalytic sites of the key enzymes that fix CO 2 in nature, [8] chemists have been interested in examining their potentialities for this particular task.…”

Tuning Electronic Structures of Covalent Co Porphyrin Polymers for Electrocatalytic CO 2 Reduction in Aqueous Solutions

“…24,25 A variety of metal complexes of polypyridines, [26][27][28] cyclams, [29][30][31] porphyrins, [32][33][34][35][36][37][38] and corroles, 39,40 have been identified as efficient CO 2 RR electrocatalysts in non-aqueous solutions. By studying these molecular catalysts, knowledge of improving catalyst performance has been gained, including tuning electronic structures, 41,42 installing proton relays, 43,44 and introducing hydrogen-bonding and electrostatic interactions. 34,[45][46][47][48] However, due to the limited water solubility and poor electronic conductivity, molecular catalysts are required to be loaded on electrode materials for electrocatalysis in aqueous solutions.…”

Outer-coordination sphere in multi-H+/multi-e–molecular electrocatalysis

“…A few examples of such enzymes are: (1) hydrogenases, which catalyze reversible H 2 evolution reactions in aqueous media at or near thermodynamic potential (Madden et al, 2012;Shafaat, 2021), (2) cytochrome c oxidase (CcO), which selectively reduces O 2 with 4H + /4e - (Kaila et al, 2010;Wikstro ¨m et al, 2015), and (3) carbon monoxide dehydrogenases (CODH), which reversibly catalyze the reduction of CO 2 to CO (Svetlitchnyi et al, 2001). Thus, such enzymatic mechanisms have inspired the study of redox reactions in molecular electrocatalysis where the selective coupling of H + and eis the central focus (Amanullah et al, 2021). Although establishing a bioidentical environment in synthetic models is challenging, research efforts to incorporate nature's features into molecular electrocatalysts have afforded promising results (Amanullah et al, 2021;Dey et al, 2017).…”

“…Thus, such enzymatic mechanisms have inspired the study of redox reactions in molecular electrocatalysis where the selective coupling of H + and eis the central focus (Amanullah et al, 2021). Although establishing a bioidentical environment in synthetic models is challenging, research efforts to incorporate nature's features into molecular electrocatalysts have afforded promising results (Amanullah et al, 2021;Dey et al, 2017). In this context, the concept of a second coordination sphere integrated with the catalyst's active site is the state-of-the-art approach.…”