Macroporous Monolithic Pt/γ-Al2O3 and K–Pt/γ-Al2O3 Catalysts Used for Preferential Oxidation of CO

Abstract

Macro-porous monolithic c-Al 2 O 3 was prepared by using macro-porous polystyrene monolith foam as the template and alumina sol as the precursor. Platinum and potassium were loaded on the support by impregnation method. TG, XRD, N 2 adsorption-desorption, SEM, TEM, and TPR techniques were used for catalysts characterization, and the catalytic performance of macro-porous monolithic Pt/c-Al 2 O 3 and K-Pt/c-Al 2 O 3 catalysts were tested in hydrogen-rich stream for CO preferential oxidation (CO-PROX). SEM images show that the macropores in the macro-porous monolithic c-Al 2 O 3 are interconnected with the pore size in the range of 10 to 50 lm, and the monoliths possess hierarchical macro-meso(micro)-porous structure. The macro-porous monolithic catalysts, although they are less active intrinsically than the particle ones, exhibit higher CO conversion and higher O 2 to CO oxidation selectivity than particle catalysts at high reaction temperatures, which is proposed to be owing to its hierarchical macro-meso(micro) -porous structure. Adding potassium lead to marked improvement of the catalytic performance, owing to intrinsic activity and platinum dispersion increase resulted from K-doping. CO in hydrogen-rich gases can be removed to 10 ppm over monolithic K-Pt/c-Al 2 O 3 by CO-PROX.

A comparative study of ZnAl2O4 nanoparticles synthesized from different aluminum salts for use as fluorescence materials

“…The first weight loss stage is seen at a low temperature range (before 200 °C) and corresponds to the evaporation of surface water in the ZnAl 2 O 4 xerogel precursors2526. The second weight loss stage (around 200–250 °C) is due to the evaporation of structural water2526. The third weight loss stage (between 250–400 °C) is due to the decomposition of small molecular organic compounds.…”

Transformation of a Pt–CeO2 Mechanical Mixture of Pulsed‐Laser‐Ablated Nanoparticles to a Highly Active Catalyst for Carbon Monoxide Oxidation

“…Highly dispersed platinum nanoparticles (NPs) deposited on oxide supports are commonly used as the active components of catalysts for practically important processes, such as neutralization of harmful gases in automobile converters, reactions in fuel cells, preferential oxidation of carbon monoxide (PROX) reaction, and CO oxidation …”

Sol-Gel Synthesis of Non-Silica Monolithic Materials

“…Alumina monoliths modified with platinum and potassium were applied as catalysts for preferential CO oxidation in hydrogen-rich stream and showed spurious support properties compared to macroporous honeycomb structured and microporous reactors [9]. Hierarchically porous carbon monolith (HPCM) has been reported to be effective supports for supercapacitive materials like aniline or LiFePO 4 [10,11].…”