Universal strategy engineering grain boundaries for catalytic oxidative desulfurization

The low-coordinated atoms such as edges, single atoms and vacancies have been widely determined as reactive sites for catalytic oxidative desulfurization. However, the grain boundaries (GB) as a favorable atomic configuration has been ignored. In this work, a universal strategy is proposed to engineer grain boundaries into oxides via facile two-step growth. Take the W18O49 nanowires as an example, the engineered GB can work as reactive sites to build stronger interfacial molecular interactions with dibenzothiophene (DBT) due to the low-coordinated W atoms with local electron-rich state, promoting the surface adsorption and activation performance towards DBT. Moreover, the molecular oxygen activation capacity is improved by GB to yield more superoxide radical relative to W18O49. Benefiting from these features, the GB-W18O49 deliver a greatly improved catalytic oxidative desulfurization behavior relative to W18O49 nanowires, in which 97.7% DBT can be removed by GB-W18O49 in 5 h but only 40.4% of W18O49 nanowires.