Executive Summary : | The emission of sulfur compounds from the combustion of liquid fuels, which contribute to acid rain and respiratory issues, has led to strict rules on sulfur content in India. Since April 2020, the sulfur content in motor fuels has been reduced to 10 ppm, making ultradeep sulfur removal crucial. Hydrodesulfurization (HDS) is inefficient in removing refractory sulfur compounds, leading to ultralow sulfur fuels and increased processing and fuel costs. Oxidative desulfurization (ODS) is an alternative method for removing sulfur compounds at mild conditions. ODS involves the facile oxidation of RS compounds to sulfones using a suitable catalyst and oxidant, allowing a single cycle of HDS to treat remnant sulfur compounds under moderate conditions, ensuring 100% sulfur removal. However, ODS faces issues such as poor mass transport of sulfur, excessive need for H?O? due to unproductive decomposition, and inhibition by olefins, alkanes, and nitrogen compounds of fuel feedstocks. To address these issues, new carbon-supported polyoxometalates with low-valent metal sites are proposed. These reusable and amphipathic catalysts can rapidly activate H2O2 and enhance mass transfer through Pickering emulsion. These catalysts are easily preparable, affordable, and efficient, providing a platform for ODS as a complementary to HDS. By ensuring a straightforward, efficient, and low-cost ODS, the proposed ODS catalysts may achieve industrialization of ODS as a complementary to HDS, promoting a SOx-free environment at reduced cost and energy conditions. |