Biomimetic Approach to CO₂ Reduction

Abstract

The development of artificial photosynthetic technologies able to produce solar-fuels from CO2 reduction is a fundamental task that requires the employment of specific catalysts being accomplished. Besides, effective catalysts are also demanded to capture atmospheric CO2, mitigating the effects of its constantly increasing emission. Biomimetic transition metal complexes are considered ideal platforms to develop efficient and selective catalysts to be implemented in electrocatalytic and photocatalytic devices. These catalysts, designed according to the inspiration provided by nature, are simple synthetic molecular systems capable of mimic features of the enzymatic activity. The present review aims to focus the attention on the mechanistic and structural aspects highlighted to be necessary to promote a proper catalytic activity. The determination of these characteristics is of interest both for clarifying aspects of the catalytic cycle of natural enzymes that are still unknown and for developing synthetic molecular catalysts that can readily be applied to artificial photosynthetic devices.

Analysis of Photosynthetic Systems and Their Applications with Mathematical and Computational Models

“…Artificial photosynthesis is envisioned as a promising technique for harvesting solar energy through water splitting and CO 2 reduction to generate high-energy chemical fuels [144,[186][187][188][189][190]. Although the field of artificial photosynthesis is still in its infancy phase of research, recent advances in synthetic biology have provided a significant boost to this interdisciplinary research field.…”

“…The main goal of artificial photosynthesis is to assemble molecular systems into larger-scale constructs for replicating the natural processes of photosynthesis which is a quite challenging and complex task in itself [190]. Today, artificial photosynthesis is largely focused on understanding and mimicking the ultimate functionality of the natural photosynthetic phenomena for producing energy-rich fuel using cheap and environmentally friendly biomimetic compounds [188,190]. Thus, the essential components of an artificial photosynthetic device would be: (i) a light harvester (e.g., semiconductor) for converting solar photons to excited states, generation of charge-separation and regulation of the flow of collected excitation energy to the reaction sites, (ii) a reduction active reaction site and an oxidation active reaction site, where conversion of excited states to redox potential occurs, (iii) molecular catalysts (i.e., transition metal complexes) to assist water splitting and CO 2 reduction system, and (iv) linkages of different molecular and nano-and macro-scale components of artificial photosynthetic elements [144,188,189,191].…”

Influence of the Greater Protein Environment on the Electrostatic Potential in Metalloenzyme Active Sites: the Case of Formate Dehydrogenase

“…1,2 Understanding the structure and function of these enzymes can enable design strategies for molecular catalysts with high activity and selectivity necessary for industrial use. [3][4][5][6] CO2 reduction remains a challenging chemical reaction that is not industrially viable [7][8][9][10] but is carried out efficiently and selectively by formate dehydrogenase (FDH) enzymes. [11][12][13][14] Mo/Wcontaining FDHs convert CO2 reversibly to formate (HCOO − ), a chemical fuel and H2 storage compound.…”

Understanding the Role of Geometric and Electronic Structure in Bioinspired Catalyst Design: the Case of Formate Dehydrogenase

“…Sustained experimental effort towards the understanding of both biological enzymes and bioinspired synthetic inorganic molecular transition metal catalysts has led to the increased availability of properties and structures of both enzymes and molecular complexes. [1][2][3][4][5][6][7][8] Computational first-principles, quantum mechanical (QM, e.g., with density functional theory or DFT) and multi-scale (i.e., mixed quantum mechanics/molecular mechanics, QM/MM) modeling plays an essential role in revealing properties of short-lived catalytic intermediates and elucidating structure-property relationships. Nevertheless, challenges associated with comparing enzyme properties to their molecular mimics has limited the ability to understand similarities and differences of bioinspired molecular catalysts to enzymes.…”