Modulating Lewis acid sites via P-doping to enable SO₂-tolerant catalytic oxidation

SO₂-induced catalyst deactivation has been a major obstacle to the practical application of transition metal oxide (TMO) catalysts. Herein, P-doped MnO₂ catalysts have been designed and achieved excellent performance on SO₂-tolerant toluene oxidation. P-doping can tailor the local chemical environment of the intrinsic Lewis acid site, namely Mn, to contribute to a much stronger and more accessible Lewis acid site. The electron enrichment and abundant surface oxygen vacancies boost the activation of surface lattice oxygen. More importantly, the effective synergy of the Lewis acid site and surface lattice oxygen enhances the activation of toluene and the conversion of intermediates, reasonably, yielding exceptional performance that closely resembles noble metal catalysts. In particular, the intensified Lewis acid weakens SO₂ chemisorption and suppresses the sulfation of Mn species, thus endowing the catalyst with robust durability to SO₂. This work gives a new insight into designing SO₂-tolerant TMO catalysts by modulating surface acid sites.