Investigation of carbon monoxide gas adsorption on the Al2O3/Pd(NO3)2/zeolite composite film

Nastaran Mozaffari,Alireza Haji Seyed Mirzahosseini,Amir Hossein Sari,Leila Fekri Aval

doi:10.1007/s40094-019-00360-6

Abstract

In this study, Al2O3/Pd(NO3)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 (qmax) 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 Al2O3/Pd(NO3)2/zeolite adsorbents. Results indicated that CO adsorption follows the pseudo-second-order model well according to regression coefficient value (R2 = 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 Al2O3/Pd(NO3)2/zeolite adsorbent indicated an effective adsorption by obtained results.

Highlights

Carbon monoxide (CO) is an achromatic, odorless and tasteless gas that can be poisonous for humans due to serious threats for the environment including acid rain, ozone depletion and secondary pollutants production [1, 2]
The concentration of adsorbed CO gas was increased by passing time until 216th seconds and it reached a saturation level of 5 mg L−1 due to the increase of contact surface area of adsorbent particles with CO gas molecules
Adsorption efficiency (R%) which showed the performance of adsorbent for CO adsorption was increased by increasing time and increasing concentration of adsorbed CO gas until it reached the saturation level with the maximum value of 97%

Summary

Introduction

Carbon monoxide (CO) is an achromatic, odorless and tasteless gas that can be poisonous for humans due to serious threats for the environment including acid rain, ozone depletion and secondary pollutants production [1, 2]. As the major aim of the present study, Pd(NO3)2, zeolite and A l2O3 were loaded on glass substrates by roll coating technique to improve the ability of adsorbents for CO adsorption and increase the range of reactions between CO gas molecules and adsorbents surface. The adsorption capacity and efficiency of A l2O3/Pd(NO3)2/ zeolite composite films were calculated which are equal to 111.16 (mg g−1) and 97%, respectively, and adsorption kinetic mechanism was studied by pseudo-first-order, pseudo-second-order, and intra-particle diffusion models.

Results

Conclusion