Cuprous ion-based zeolites have been proven as promising carbon monoxide (CO) adsorbents by virtue of their excellent adsorption and regeneration properties due to π complexation. However, existing preparation methods still suffer from the problems of a cumbersome process and low loading amounts of cuprous ions. Herein, we proposed a one-step synthesis strategy of using ethanol as a solvent to provide a reducing protective environment, which enabled the facile and controllable preparation of highly dispersed CuCl over 5A zeolites. Using CuCl as a copper source, to ensure the integrity of the 5A zeolite structure, CuCl species were directly loaded onto the 5A support in one step. Ethanol solution could effectively protect Cu(I) from being oxidized by oxygen in air and improve the stability of cuprous ions in Cu(I)/ 5A adsorbents. The results demonstrated that the Cu(I)/5A prepared by this method exhibited a superior CO adsorption performance to the pristine 5A zeolite. The adsorption capacity of CO over Cu(I)/5A attained 3.44 mmol•g −1 at 298 K and atmospheric pressure, which was evidently superior to those of CuY (2.7 mmol•g −1 ) and CuSAPO34 (1.84 mmol•g −1 ) reported in the literature, while the adsorption capacity of H 2 was only 0.069 mmol•g −1 under the same condition. According to the ideal solution adsorption theoretical model, CO was preferentially adsorbed and the IAST selectivity of CO in the CO/H 2 binary mixture over Cu(I)/5A was about 273.4. This study provides a novel and effective way to synthesize high-efficiency CO adsorbents.

Recently, the investigation of high-efficiency adsorbents for CO adsorption and separation has gradually become a research focus with carbon energy chemistry developing and environmental protection requirement enhancing. The adsorption performance of CO would be devitalized under a humid environment, although the traditional molecular sieves could serve as an effective adsorbent toward CO adsorption under an anhydrous atmosphere. In this work, a strategy of silanization modification was proposed to enhance the performance of CO adsorption by restraining the surface occupied by competitive water molecules due to the hydrophilic nature of silica hydroxyl groups on the 5A molecular sieves. A series of hydrophobic CO adsorbents (X-B-5A) were successfully prepared via impregnation using butyltrichlorosilane (BTS) as a hydrophobic agent, toluene as a dispersion solution, and commercial 5A molecular sieves as a raw material. The effect of different concentrations of BTS in toluene solution on hydrophobicity and CO adsorption performance was investigated. The results showed that the hydrophobicity of X-B-5A was significantly increased after silanization modification. Additionally, the water contact angle of 0.004-B-5A increased from 20° to 154°, and the static water vapor adsorption capacity was reduced from 27.5 to 6.0% at 35 °C. The CO static adsorption capacity of 0.004-B-5A still reached 1.54 mmol/g, which was only 14.6% lower than that of pristine 5A molecular sieves. Additionally, the dynamic adsorption capacity of CO over the as-prepared X-B-5A was significantly enhanced compared to pristine 5A molecular sieves in the presence of moisture. The as-prepared hydrophobic adsorbents exhibited satisfactory CO adsorption performance and high thermal stability in a humid environment. This work presents a novel strategy for the preparation of adsorbents toward CO adsorption employed under a high relative humidity environment.