Highly efficient catalytic combustion of o-dichlorobenzene over lattice-distorted Ru/OMS-2: The rapidly replenishing effect of surface adsorbed oxygen on lattice oxygen

Cryptomelane-type catalysts (OMS-2) are known as their highly active lattice oxygen and unique structure with isolated K+ in open one dimensional (1D) tunnel. According to Mars van Krevelen (MVK) mechanism, the supplement of lattice oxygen by surface adsorbed oxygen is the critical step in catalytic oxidation reaction. Many researchers unilaterally tried to promote surface adsorbed oxygen or lattice oxygen reactivity to enhance OMS-2 catalytic performance. In this work, a more direct strategy was explored to improve the replenishing effect of surface adsorbed oxygen on lattice oxygen. Through etching OMS-2 nanorod with different crystallinity by weakly acidic RuCl3 solution, lattice-distorted Ru/OMS-2 catalysts were prepared which have abundant surface defects, lower Mn-O force constant, plentiful surface adsorbed oxygen and enhanced redox ability. Electronegative surface oxygen species (such as O-2(-) and O-) were enriched by the adsorption of surface isolated Mn4+ ions which were supplement of K+ vacancies to balance charge. The greatly enhanced catalytic activity of OMS-2 on o-dichlorobenzene (o-DCB) combustion could be attributed to stable structure, excellent redox ability promoted by RuO2 and rapidly replenishing effect of surface adsorbed oxygen on lattice oxygen.