H. Seelajaroen, A. Bakandritsos, M. Otyepka and R. Zbořil, "Immobilized Enzymes on Graphene as Nanobiocatalyst," ACS APPLIED MATERIALS & INTERFACES, vol. 12, iss. 1, pp. 250-259, 2020.
DOI: 10.1021/acsami.9b17777, IF = 8.456
Abstract: Using enzymes as bioelectrocatalysts is an important step toward the next level of biotechnology for energy production. In such biocatalysts, a sacrificial cofactor as an electron and proton source is needed. This is a great obstacle for upscaling, due to cofactor instability and product separation issues, which increase the costs. Here, we report a cofactor-free electroreduction of CO2 to a high energy density chemical (methanol) catalyzed by enzyme–graphene hybrids. The biocatalyst consists of dehydrogenases covalently bound on a well-defined carboxyl graphene derivative, serving the role of a conductive nanoplatform. This nanobiocatalyst achieves reduction of CO2 to methanol at high current densities, which remain unchanged for at least 20 h of operation, without production of other soluble byproducts. It is thus shown that critical improvements on the stability and rate of methanol production at a high Faradaic efficiency of 12% are possible, due to the effective electrochemical process from the electrode to the enzymes via the graphene platform.
A. Goswami, R. G. Kadam, J. Tuček, Z. Sofer, D. Bouša, R. S. Varma and M. B. Gawande, "Fe(0)-embedded thermally reduced graphene oxide as efficient nanocatalyst for reduction of nitro compounds to amines," CHEMICAL ENGINEERING JOURNAL, vol. 382, iss. , pp. 122469, 2020.
DOI: 10.1016/j.cej.2019.122469, IF = 8.355
Abstract: The recent progress in metal nanoparticle-based catalytic systems has prompted the research community to focus on combining the unique physicochemical properties with their catalytic activities. In this context, magnetic nanomaterials offer significant advantage as they can be separated after the catalytic reaction and reused. Among such systems, Fe-based nanoparticles are undeniably the most popular as they can be synthesized from the earth-abundant resources. However, in view of the poor chemical stability of nanoscale zero-valent iron (nZVI) particles during the reaction process, their use in advanced catalytic systems is still challenging. Herein, we present a Fe(0) species embedded in a thermally reduced graphene oxide matrix (Fe/TRGO) as a nanocatalyst for the reduction of nitro compounds. The catalyst exhibits high substrate scope with high yield and selectivity and can be recycled up to four times without any significant loss in activity. The unique rGO (reduced graphene oxide)-entrapped doughnut-shaped structure of the Fe(0) species, accompanied by the thin oxide protection layer, is responsible for the superior catalytic activity. Due to the scalable synthesis and high catalytic efficiency the catalyst offers a real application potential in industrial transformations of nitro compounds.