In-plasma-catalysis for NO(x) degradation by Ti(3+) self-doped TiO(2−x)/γ-Al(2)O(3) catalyst and nonthermal plasma

In an attempt to realize the efficient treatment of NO(x), a mixed catalyst of Ti(3+) self-doped TiO(2−x) and γ-Al(2)O(3) was constructed by reducing commercial TiO(2). The degradation effect on NO(x) was evaluated by introducing the mixed catalyst into a coaxial dual-dielectric barrier reactor. It was found that the synthesized TiO(2−x) could achieve considerable degradation effects (84.84%, SIE = 401.27 J L(−1)) in a plasma catalytic system under oxygen-rich conditions, which were better than those of TiO(2) (73.99%) or a single plasma degradation process (26.00%). The presence of Ti(3+) and oxygen vacancies in TiO(2−x) resulted in a relatively narrow band gap, which contributed to catalyzing deeply the oxidation of NO(x) to NO(2)(−) and NO(3)(−) during the plasma-induced “pseudo-photocatalysis” process. Meanwhile, the TiO(2−x) showed an improved discharge current and promoted discharge efficiency, explaining its significant activation effect in the reaction. Reduced TiO(2−x) could achieve an impressive degradation effect in a long-time plasma-catalysis process, and still maintained its intrinsic crystal structure and morphology. This work provides a facile synthesis procedure for preparing Ti(3+) self-doped TiO(2−x) with practical and scalable production potential; moreover, the novel combination with plasma also provides new insights into the low-temperature degradation of NO(x).