Overview of Carbon Monoxide Adsorption Performance of Pristine and Modified Adsorbents

Abstract

Carbon monoxide (CO) is a key material in C1 chemistry for chemical production and CO2 reduction, whereas in applications, such as H2 for fuel cells, its concentration must be kept below 0.2 ppm. Adsorption technology is useful for both CO removal and production to provide environmental sustainability for the energy and chemical industries. In this review, the CO adsorption performances of various adsorbents, such as activated carbons, zeolites, metal–organic frameworks, activated alumina, mesoporous silicas, and their modified adsorbents, are collected, and their physical and chemical properties and CO selectivities are summarized. Cu+ impregnation is a powerful and widely used modification method to enhance the CO adsorption of adsorbents. Therefore, the preparation methods and their effects on CO adsorption are also compared and reviewed. The data and analysis in this review can provide insights for the development of novel adsorbents and processes for CO removal and production.

Mg-incorporated sorbent for efficient removal of trace CO from H2 gas

“…Numerous sorbents had reported considerable sorption performance, but powder sorbents often pose problems in packed or fluidized bed applications due to their associated high-pressure drop and potential for process contamination 16 . Thus, given these factors, a pellet Cu-impregnated activated carbon (AC-Cu + ), with outstanding performance among the reported CO sorbents 37 , served as a control group, and the performance evaluation incorporated both static and dynamic behavior.…”

“…To overcome these limitations, it is essential to develop sorbents with a robust CO sorption capacity (i.e., within the ppm range) that do not generate CO 2 and thus avoid the need for additional separation processes. However, the majority of CO sorbent research to date has concentrated on enhancing CO sorption within a pressure range of 100–200 kPa, which is more useful for CO production than for removal 16 , 17 . Additionally, H 2 products from H 2 production or purification processes contain a few percent or ppm of CO (Supplementary Table 1 ).…”

“…Additionally, H 2 products from H 2 production or purification processes contain a few percent or ppm of CO (Supplementary Table 1 ). Notably, while previous studies on powder sorbents have demonstrated a high CO sorption performance at 100–200 kPa of CO 16 , a research gap exists regarding CO sorption capacity at ppm levels. Simultaneously, investigations into applying them in a stable pellet form for practical process applications are also lacking.…”

“…Cu + has been widely employed to facilitate CO sorption through both π-back donation and σ-bond formation 19 , but sorbents containing Cu + experience aggregation during regeneration and oxidation when exposed to air 16 , 20 . In fact, a material suitable for CO sorption needs a high CO sorption capacity, oxidation resistance, and recycling ability, even at ultra-low CO concentrations.…”

Targeted Synthesis of a Highly Stable Aluminium Phosphonate Metal–Organic Framework Showing Reversible HCl Adsorption

“…[2] The progress achieved within the last 25 years was recently summarized and impressively demonstrates the outstanding properties that can be achieved, particularly in adsorption related applications. [3] For exam-ple, specific MOFs have been discovered that show exceptional uptake or selectivity towards gases and vapours such as C 2 H 2 , [4] CH 4 , [5] CO, [6] CO 2 , [7] SO 2 , [8] NO 2 [9] or H 2 S. [10] Adsorption of the latter adsorbates is especially challenging, as it requires MOFs with exceptionally high chemical stability. Those formed from tri-and tetravalent metal ions such as Al 3 + , Cr 3 + , Ti 4 + or Zr 4 + , have proven particularly suitable for such selective adsorptions.…”