Well-defined and highly stable AlNi composite pillared clay supported PdOx nanocrystal catalysts for catalytic combustion of benzene

In the study, the effects of synthesis conditions for AlNi composite pillaring agents (Al/Ni molar ratio, aging temperature and aging time) on the structure and stability of AlNi pillared clays (AlNi-PILC) were investigated. And the results showed that the above synthesis factors could control and adjust the specific surface area, pore volume and basal spacing of AlNi-PILC. The formation of spinal NiAl 2 O 4 markedly improved the thermal stability and anti-sintering properties of AlNi-PILC and maintain a stable mesoporous structure. Pd/AlNi-PILC nanocrystalline catalyst obtained by using a high-temperature solution-phase reduction method presented a strong interaction between the active species PdO x (x = 0, 1) and AlNi-PILC. The PdO x nanocrystals had excellent stability with a small diameter (1–2 nm) and the nanocrystals were evenly mono dispersed on the surface of AlNi-PILC. Thus, 0.2%Pd/AlNi-PILC exhibited excellent catalytic oxidation properties and completed catalytically oxidize low concentrations of benzene at 250 °C. Furthermore, 0.2%Pd/AlNi-PILC maintained 90% benzene conversion at 240 °C after a continuous reaction for 1000 h in dry air. And in either wet conditions or in the chlorine-containing VOCs, 0.2%Pd/AlNi-PILC maintained high catalytic activity and thus showed potential in industrial applications.