Encapsulating uniform Pd nanoparticles in TS-1 zeolite as efficient catalyst for catalytic abatement of indoor formaldehyde at room temperature

One-pot hydrothermal method was adopted to synthesize Pd catalysts encapsulated by TS-1 zeolites [Pd@TS1(x)]. The strategy could effectively improve Pd dispersion and reduce the sizes of Pd nanoparticles (NPs). These Pd NPs with an average size of 2.2-3.5 nm were well encapsulated inside the TS-1 matrix. The Pd@TS-1(x) catalysts with Si/Ti molar ratio of 50 exhibited the best catalytic activity for HCHO oxidation [the temperature for complete oxidation of HCHO was 25 degrees C under the reaction conditions of space velocity (SV) = 100,000 mL/(g x h) and relative humidity (RH) = 35 %]. In combination with CO chemisorption, H-2-TPR, and HCHO-TPSR, the excellent catalytic performance of Pd@TS-1(50) was ascribed to small size of Pd domain, high Pd dispersion, and prompt surface reaction. Benefit from the core-shell like structure exposing a hydrophobic silicon-rich surface, the Pd@TS-1(50) catalyst also possessed satisfactory stability for a long-term test.