As the environment and the human body face harmful effects of toxic gases such as carbon monoxide (CO), many research efforts have been directed toward elimination of these species through various adsorption processes. Unique properties of γ-Al 2 O 3 in CO capture have led us to prepare SnO 2 /Al 2 O 3 , Ni/Al 2 O 3 , and SnO 2 /Ni/Al 2 O 3 composite nanocrystalline films using the roll-coating method. The crystalline structure and morphology of the coatings were investigated using X-ray diffraction and field-emission scanning electron microscopy, respectively. The performed analyses revealed the complex microstructure of the coatings composed of fine grains and welldispersed nanoparticles that aggregated to form larger welldeveloped clusters. Following this, adsorption characteristics of the samples were measured using the KIMO KIGAZ 210 continuous flow gas analyzer. Finally, the kinetics of the CO adsorption process was studied using various diffusion models: pseudo-first-order, pseudo-second-order, and intraparticle.

In this study, Al 2 O 3 /Pd(NO 3) 2 /zeolite composite films have been fabricated by roll coating method and characterized by X-ray diffraction, energy-dispersive X-ray spectroscopy and field emission scanning electron microscopy. The gas adsorption was tested in an experimental setup by a continuous gas analyzer KIMO KIGAZ 210 at constant temperature and pressure (32 °C and 1.5 bar) and as a function of reaction time (s). The inlet CO gas concentration was 150 mg L −1 , and the saturation level of CO gas concentration was 5 mg L −1. The maximum adsorption capacity (q max) and maximum adsorption efficiency (%) were calculated as 111.16 mg g −1 and 97%, respectively. Pseudo-first-order, pseudo-second-order, and intra-particle diffusion models were investigated to kinetic study of CO adsorption on Al 2 O 3 /Pd(NO 3) 2 /zeolite adsorbents. Results indicated that CO adsorption follows the pseudo-second-order model well according to regression coefficient value (R 2 = 0.98), and the value of pseudo-second-order rate constant of adsorption was obtained as 2 × 10 −5 g mg −1 s −1. According to the intra-particle diffusion model, adsorption is affected by only one process. So, adsorption of CO by Al 2 O 3 /Pd(NO 3) 2 /zeolite adsorbent indicated an effective adsorption by obtained results.

CO gas adsorption has become a topic of great significance and worthy of investigation. The purpose of this study was to explore the CO adsorption of Al 2 O 3 /Zeolite composite films prepared by a roll coating method. XRD, FESEM, and EDX analyses have been used to study the structural, morphological, and elemental properties of Al 2 O 3 /Zeolite composite films. A gas analyzer was used to probe CO gas adsorption on the composite films at a constant temperature and pressure. The concentration of inlet CO gas and saturation level was 190 and 4 mg L −1 , respectively. The maximum values of adsorption efficiency and uptake capacity were measured at 97.89% and 213.9 mg g −1 . To determine the kinetic study, three models were investigated: pseudo-first-order, pseudo-second-order, and intra-particle diffusion. The pseudo-second-order model was suitable for CO adsorption by Al 2 O 3 /Zeolite adsorbent. Additionally, the rate-controlling step for Al 2 O 3 /Zeolite adsorbent was identified through the intra-particle diffusion model.

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The aim of this article was the fabrication of Al2O3/Pd(NO3)2/zeolite adsorbent through roll-coating technique for CO gas adsorption. Transmission electron microscopy (TEM), field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and energy-dispersive x-ray spectroscopy (EDX) were performed to investigate the morphological, structural, and elemental properties of Al2O3/Pd(NO3)2/zeolite adsorbent. A continuous gas analyzer KIMO KIGAZ 210 was applied for testing CO gas adsorption on as-present adsorbent in an experimental set-up. The calculated amounts of adsorption capacity at equilibrium time was 111.16 mg g-1 according to the previous published article. The Elovich, Avrami, and Fractional power kinetic models were studied for this adsorbent. The equal value of experimental and theoretical adsorption capacity at equilibrium time as well as the unit value of regression coefficient indicate that Avrami kinetic model was a suitable model to describe Co removal through Al2O3/Pd(NO3)2/zeolite adsorbent.