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Catalytic conversion of CO 2 to chemicals and fuels is a "two birds, one stone" approach toward solving the climate change problem and energy demand−supply deficit in the modern world. Recent advances in mechanistic insights and design of suitable catalysts for direct thermocatalytic hydrogenation of CO 2 to C1 products are thoroughly discussed in this Review. The role of catalyst composition and process conditions in determining the selective pathways to various products like carbon monoxide, methanol, methane, and dimethyl ether has been overviewed in light of thermodynamic and kinetic considerations. After extensive elaboration of the main motivation of the reaction pathways, catalytic roles, and reaction thermodynamics, we summarize the most important macroscopic aspects of CO 2 hydrogenation technology development, which include reactor innovations, industrial status of the technology, life cycle assessment and technoeconomic analysis. Finally, a critical perspective on the future challenges and opportunities in both the core fronts and overall technology development is provided.

Semiconductor materials for efficient hard radiation detection are identified by combining a powerful chemical concept called dimensional reduction and precise theoretical electronic structure calculations. After more than 50 years of research and development in the field, this constitutes a significant step forward in the search for new detector materials.

The electrochemical hydrogen evolution reaction (HER) is a well-studied reaction which involves the reduction of protons for hydrogen production. Pd-based compounds are expected to have activity on par with or better than the expensive state-of-the-art Pt and can be considered as the future materials for the HER.

Fungal peroxygenases are novel extracellular heme-thiolate biocatalysts that are capable of catalyzing the selective monooxygenation of diverse organic compounds, using only H2O2 as a cosubstrate. Little is known about the physiological role or the catalytic mechanism of these enzymes. We have found that the peroxygenase secreted by Agrocybe aegerita catalyzes the H2O2-dependent hydroxylation of linear alkanes at the 2-position and 3-position with high efficiency, as well as the regioselective monooxygenation of branched and cyclic alkanes. Experiments with n-heptane and n-octane showed that the hydroxylation proceeded with complete stereoselectivity for the (R)-enantiomer of the corresponding 3-alcohol. Investigations with a number of model substrates provided information about the route of alkane hydroxylation: (a) the hydroxylation of cyclohexane mediated by H218O2 resulted in complete incorporation of 18O into the hydroxyl group of the product cyclohexanol; (b) the hydroxylation of n-hexane-1,1,1,2,2,3,3-D7 showed a large intramolecular deuterium isotope effect [(kH/kD)obs] of 16.0 ± 1.0 for 2-hexanol and 8.9 ± 0.9 for 3-hexanol; and (c) the hydroxylation of the radical clock norcarane led to an estimated radical lifetime of 9.4 ps and an oxygen rebound rate of 1.06 × 1011 s−1. These results point to a hydrogen abstraction and oxygen rebound mechanism for alkane hydroxylation. The peroxygenase appeared to lack activity on long-chain alkanes (> C16) and highly branched alkanes (e.g. tetramethylpentane), but otherwise exhibited a broad substrate range. It may accordingly have a role in the bioconversion of natural and anthropogenic alkane-containing structures (including alkyl chains of complex biomaterials) in soils, plant litter, and wood.

A [2 + 2] Schiff base type condensation between 5,10,15,20-tetrakis(4-aminophenyl)porphyrin (TAP) and 1,3,6,8-tetrakis (4-formylphenyl) pyrene (TFFPy) under solvothermal condition yields a crystalline, quasi-two-dimensional covalent organic framework (SB-PORPy-COF). The porphyrin and pyrene units are alternatively occupied in the vertex of 3D triclinic crystal having permanent microporosity with moderately high surface area (∼869 m g) and promising chemical stability. The AA stacking of the monolayers give a pyrene bridged conducting channel. SB-PORPy-COF has been exploited for metal free hydrogen production to understand the electrochemical behavior using the imine based docking site in acidic media. SB-PORPy-COF has shown the onset potential of 50 mV and the Tafel slope of 116 mV dec. We expect that the addendum of the imine based COF would not only enrich the structural variety but also help to understand the electrochemical behavior of these class of materials.

The extracellular heme-thiolate peroxygenase from Agrocybe aegerita (AaeAPO) has been shown to hydroxylate alkanes and numerous other substrates using hydrogen peroxide as the terminal oxidant. We describe the kinetics of formation and decomposition of AaeAPO compound I upon its reaction with mCPBA. The UV–vis spectral features of AaeAPO–I (361, 694 nm) are similar to those of chloroperoxidase–I and the recently–described cytochrome P450–I. The second–order rate constant for AaeAPO–I formation was 1.0 (±0.4) ×107 M−1s−1 at pH 5.0, 4 °C. The relatively slow decomposition rate, 1.4 (±0.03) s−1, allowed the measurement of its reactivity toward a panel of substrates. The observed rate constants, k2’, spanned five orders of magnitude and correlated linearly with bond dissociation enthalpies of strong C–H bond substrates with a log k2’ vs. BDE slope of ~ 0.4. However, the hydroxylation rate was insensitive to C–H BDE below 90 kcal/mol, similar to the behavior of the t-butoxy radical. The shape and slope of the Brønsted-Evans-Polanyi plot indicate a symmetrical transition state for the stronger C–H bonds and suggest entropy control of the rate in an early transition state for weaker C–H bonds. The AaeAPO–II FeIVO–H BDE was estimated to be ~ 103 kcal/mol. All results support the formation of a highly reactive AaeAPO oxoiron(IV) porphyrin radical cation intermediate that is the active oxygen species in these hydroxylation reactions.

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