From CO activation to catalytic reduction: a metal-free approach.

Over exploitation of natural resources and human activities are relentlessly fueling the emission of CO in the atmosphere. Accordingly, continuous efforts are required to find solutions to address the issue of excessive CO emission and its potential effects on climate change. It is imperative that the world looks towards a portfolio of carbon mitigation solutions, rather than a single strategy. In this regard, the use of CO as a C1 source is an attractive strategy as CO has the potential to be a great asset for the industrial sector and consumers across the globe. In particular, the reduction of CO offers an alternative to fossil fuels for various organic industrial feedstocks and fuels. Consequently, efficient and scalable approaches for the reduction of CO to products such as methane and methanol can generate value from its emissions. Accordingly, in recent years, metal-free catalysis has emerged as a sustainable approach because of the mild reaction conditions by which CO can be reduced to various value-added products. The metal-free catalytic reduction of CO offers the development of chemical processes with low cost, earth-abundant, non-toxic reagents, and low carbon-footprint. Thus, this perspective aims to present the developments in both the reduction and reductive functionalization chemistry of CO during the last decade using various metal-free catalysts.