Enhanced Oxygen Activation Achieved by Robust Single Chromium Atom-Derived Catalysts in Aerobic Oxidative Desulfurization

Abstract

Oxidative desulfurization (ODS) plays critical roles in the production of high-quality sulfur impurity-free fuels, especially procedures using molecular oxygen as the sole oxidant. However, the state-of-the-art systems still rely on noble metal nanocatalysts, with deactivation issues caused by coking and sintering still present. Herein, leveraging the merits of single-atom catalysts (SACs) with earth-abundant metal cores and robust nanoporous supports, a series of catalysts composed of homogeneously distributed single chromium atoms anchored on multiwalled carbon nanotubes were fabricated and deployed to catalyze the aerobic ODS transformation. Adopting aromatic sulfur compound (ASC)-containing alkanes as a model system with molecular oxygen as the oxidant, efficient oxygen-to-active O2 •– transformation and subsequent ASCs-to-sulfone conversion have been achieved, with the former benefiting from the chromium-active sites and the latter arising from the robust, nanoporous, and π-conjugated architecture of the supports. The attractive catalytic performance and cycling stability of the chromium-based SACs make them promising candidates in practical sulfur species removal from liquid fuels, supplying an alternative guidance on the catalyst design toward cost-effective and energy-efficient ODS procedures.

Interface Engineering of a Bifunctional Cu-SSZ-13@CZO Core–Shell Catalyst for Boosting Potassium Ion and SO2 Tolerance

“…529.6 eV on both Cu-SSZ-13@CZO and Cu-SSZ-13@CZO-S-K. The higher binding energy is associated with the lattice oxygen from Cu, Ce, and Zr oxides, while the lower binding energy is related to the lattice oxygen from the Cu-SSZ-13 structure . The O II peak corresponds to the hydroxyl group, surface-adsorbed oxygen, and oxygen vacancies of the CZO shell .…”

“…The higher binding energy is associated with the lattice oxygen from Cu, Ce, and Zr oxides, while the lower binding energy is related to the lattice oxygen from the Cu-SSZ-13 structure. 36 The O II peak corresponds to the hydroxyl group, surface-adsorbed oxygen, and oxygen vacancies of the CZO shell. 37 The Ce 3d XPS of Cu-SSZ-13-based catalysts were divided into eight peaks, and the corresponding assignments of which are presented in Figure 3D.…”

Modulating Electronic Characteristics of Nickel Molybdate via an Effective Manganese-Doping Strategy to Enhance Oxidative Desulfurization Performance

“…Consequently, a logical reaction mechanism of ODS by MNMO-20 is proposed in Scheme . Based on the reported literature and aforementioned experimental results, , first, O 2 molecular and sulfur-containing substances are accumulated together on the catalyst surface, owing to the adsorption effect. After this, O 2 is activated by Mn and Ni sites to generate active O 2 •– radicals through a synergistic effect due to the strong electron-donating capability.…”

Group IIIA Single-Metal Atoms Anchored on Hexagonal Boron Nitride for Selective Adsorption Desulfurization via S–M Bonds

“…In the coming decades, the worldwide demand for diesel fuel will remain heavy although significant efforts have been made in renewable energy. , Diesel fuel still continues to serve as a major irreplaceable energy resource in transportation, machinery, and engineering . However, SO x will be generated by fuels containing sulfur compounds after combustion, which seriously threatens human health and the environment. − For this reason, almost all countries and regions have established stricter standards on the sulfur content of fuels. ,− In view of increasingly stringent environmental protection laws, it is extremely necessary to achieve ultra-deep desulfurization of fuels. − Conventionally, the hydrodesulfurization (HDS) process widely used in industry at this stage has certain limitations, such as high temperature and high-pressure reaction conditions in the HDS process, and it is difficult for HDS to completely remove thiophenic compounds (THs), − such as dibenzothiophene (DBT), 4-methyldibenzothiophene (4-MDBT), and 4,6-dimethyldibenzothiophene (4,6-DMDBT). Therefore, it is desirable to find an alternative process of nonhydrodesulfurization to complement HDS.…”