The industrial use of enzymes generally necessitates their immobilization onto solid supports. The well-known high affinity of enzymes for metal-organic framework (MOF) materials, together with the great versatility of MOFs in terms of structure, composition, functionalization and synthetic approaches, has led the scientific community to develop very different strategies for the immobilization of enzymes in/on MOFs. This review focuses on one of these strategies, namely, the one-pot enzyme immobilization within sustainable MOFs, which is particularly enticing as the resultant biocomposite Enzyme@MOFs have the potential to be: (i) prepared in situ, that is, in just one step; (ii) may be synthesized under sustainable conditions: with water as the sole solvent at room temperature with moderate pHs, etc.; (iii) are able to retain high enzyme loading; (iv) have negligible protein leaching; and (v) give enzymatic activities approaching that given by the corresponding free enzymes. Moreover, this methodology seems to be near-universal, as success has been achieved with different MOFs, with different enzymes and for different applications. So far, the metal ions forming the MOF materials have been chosen according to their low price, low toxicity and, of course, their possibility for generating MOFs at room temperature in water, in order to close the cycle of economic, environmental and energy sustainability in the synthesis, application and disposal life cycle.

Metal-organic framework (MOF) materials possess the widest versatility in structure, composition, and synthesis procedures amongst the known families of materials. On the other hand, the extraordinary affinity between MOFs and enzymes has led to widely investigating these materials as platforms to support these catalytic proteins in recent years. In this work, the MOF material NH₂-MIL-53(Al) has been tested as a support to immobilize by one-step methodology (in situ) the enzyme lipase CaLB from Candida antarctica by employing conditions that are compatible with its enzymatic activity (room temperature, aqueous solution, and moderate pH values). Once the nature of the linker deprotonating agent or the synthesis time were optimized, the MOF material resulted in quite efficient entrapping of the lipase CaLB through this in situ approach (>85% of the present enzyme in the synthesis media) while the supported enzyme retained acceptable activity (29% compared to the free enzyme) and had scarce enzyme leaching. The equivalent post-synthetic method led to biocatalysts with lower enzyme loading values. These results make clear that the formation of MOF support in the presence of the enzyme to be immobilized substantially improves the efficiency of the biocatalysts support for retaining the enzyme and limits their leaching.

Reducing CO₂ to CO via the reverse water–gas shift (RWGS) reaction is a promising strategy for carbon capture and utilization (CCU). In this study, tailored magnetic catalysts were designed through the pyrolysis of a Co-based MOF to form well-defined nanoparticles. As a result, carbon-encapsulated cobalt nanoparticles (Co@C) and palladium-doped cobalt nanoparticles (CoPd/Co@C) were synthesized and thoroughly characterized using a variety of techniques, including in situ X-ray absorption and diffraction experiments. These carbon-based catalysts were simultaneously used as heating agents and catalysts for the magnetically induced RWGS reaction, exhibiting remarkable activity and selectivity for syngas production. CO₂ conversions of 61.1% and 71.1% were obtained for Co@C and CoPd/Co@C (63 mT, 2 kW, 320 kHz), respectively. Using magnetic induction heating (MIH), these catalysts operate at lower local temperatures and with greater energy efficiency than conventional thermal heating, while achieving superior CO production efficiency. Notably, CoPd/Co@C achieved highly satisfactory CO production efficiency (478.5 mL_CO/kW·h), demonstrating a significant improvement compared to the analogous process utilizing magnetically induced heating. Furthermore, CoPd/Co@C exhibited unwavering stability, maintaining its performance for more than 200 h without significant degradation or need for reactivation. This study highlights the potential of MIH for industrial applications in CO₂ reduction, offering a more renewable and economically viable alternative to traditional methods.