Highly active heterogeneous hydrogenation catalysts prepared from cobalt complexes and rice husk waste

Abstract

The utilization and valorization of agricultural waste is a key strategy for the implementation of a sustainable economy and to lesser the environmental footprint of human activities on Earth. This...

CN-Doped Cobalt Oxide Composite: An Economic and Reusable Catalyst with Multitasking Catalytic Capability for Alkyne and Nitrile Hydrations and Nitro Reductions

“…29,30 Some of the heterogeneous cobalt catalyst reports for nitro reduction are shown in Scheme 1. [31][32][33] All of these reports use hazardous H 2 gas as a source of hydrogen. Our procedure circumvents all of the drawbacks by employing a hydrogen-free atmosphere and provides a greener environment by using water as a solvent, rather than toxic solvents.…”

Stepwise Growth of Copper-Based Coordination Polymer on α-MnO2 Nanorods for Sustainable Reduction of Nitroarenes

“…Heterogeneous catalysts, particularly the noble metal catalysts based on Rh, Ru, Pt, Pd, and Au, are the most attractive catalysts for the reduction of nitroarenes to aminoarenes. , Although these catalysts are highly active for this transformation, they are also highly efficient in the activation of other reducible groups like nitrile, carbonyl, and alkene, which leads to poor selectivity. , In addition, the high cost and limited availability of precious metals make them unattractive in potential industrial-scale applications. − Consequently, efforts have been made to develop heterogeneous catalysts based on cheaper non-noble transition metals, for example, Fe, Cu, Ni, and Co for the reduction of nitroarenes. − However, most of these catalytic systems require severe reaction conditions, such as higher temperatures, longer time, high catalyst amount, and toxic organic solvents. Thus, the development of cost-effective and robust heterogeneous non-noble metal catalysts for green production of aminoarenes remains an actual goal.…”

Hydrogenation of Epoxides to Anti‐Markovnikov Alcohols over a Nickel Heterogenous Catalyst Prepared from Biomass (Rice) Waste

“…[3 -5] With the aim of finding a more sustainable use of these residues, our group recently developed ways to valorize rice husk waste (RH) to prepare new materials with bio-medical, [6] and catalytical applications. [7,8] Our general strategy is to exploit the ability of pyrolyzed RH to act simultaneously as Brønsted-and Lewis-acid, and supporting metal nanoparticles onto its surface, thus conferring these composites antimicrobial and catalytic properties. The work presented herein discloses the synthesis of nickel-containing materials from rice husk, and their use as catalyst for the reductive ring-opening of epoxides to yield alcohols with anti-Markovnikov selectivity; a straightforward way to obtain primary alcohols from terminal olefin oxides.…”

“…The management of this amount of waste represents a challenge for most communities, being the current ‘solution’ the open‐field burning of the biomass, resulting in huge amounts of green‐house gas and particulate emissions to the atmosphere, which is associated with major health issues [3–5] . With the aim of finding a more sustainable use of these residues, our group recently developed ways to valorize rice husk waste (RH) to prepare new materials with bio‐medical, [6] and catalytical applications [7,8] . Our general strategy is to exploit the ability of pyrolyzed RH to act simultaneously as Brønsted ‐ and Lewis ‐acid, and supporting metal nanoparticles onto its surface, thus conferring these composites antimicrobial and catalytic properties.…”