High CO Adsorption Performance of CuCl-Modified Diatomites by Using the Novel Method “Atomic Implantation”

Abstract

An atomic implantation method was used to modify diatomite with CuCl. The CuCl/diatomite samples were characterized by different techniques, including FTIR, XRD, BET, SEM-TEM, EDX, and CO-TPR. Characterization results revealed the formation of CuCl particles of 50–60 nm highly dispersed on diatomite surface. CO adsorption measurements showed that 2CuCl/diatomite exhibits the highest CO adsorption capacity among all CuCl-modified samples with diatomite. Its CO adsorption capacity of 2.96 mmol/g at 30°C is 10 times higher than that of unmodified diatomite (0.29 mmol/g). The CO adsorption on CuCl-modified diatomites was found to fit well with the Langmuir–Freundlich model.

Overview of Carbon Monoxide Adsorption Performance of Pristine and Modified Adsorbents

“…It was reported that an increase in the adsorption temperature also contributed to the dispersion of Cu + . 45 Notably, CuCl can be easily oxidized during impregnation. Cu 2+ species were found during the mixing process, and Cu was also detected after the activation process.…”

“…24,35 As the CO adsorption capacities of pristine ACs are relatively low (up to 0.5 mmol/g; Table 1), the main role of AC is generally to adsorb CO 2 from H 2 mixtures in various H 2 PSA processes. 36−38 However, after Cu + impregnation, the CO adsorption capacity increased to ∼2.95 mmol/g at room temperature and 100 kPa (Figure 2c and Table S2), which is 35,43,45,50,52,55,69,86,98,101,107,109,110,119,125 almost equivalent to the adsorption capacities of MOFs. Therefore, ACs might be effective for the removal of CO in H 2 PSA processes.…”

“…46 As shown in Table 6, Cu/bayerite (44) and Cu/boehmite (46) exhibited high selectivity for CO compared with other components in H 2 mixtures. Cu/diatomite was prepared by the use of an "atomic implantation" method, 45 in which the impregnation and dispersion occur simultaneously. CuCl and diatomite were separately introduced into a tubular reactor divided by a film of quartz fibers.…”

“…CO adsorption isotherms on (a) pristine and (b) Cu + -impregnated adsorbents up to 100 kPa and (c) selected adsorbents up to 2000 kPa. All data were read from figures in the references. ,,,,,,,,,,,,,, …”

“…(a) Isosteric heats of adsorption and (b) CO/CO 2 selectivities of adsorbents as functions of CO adsorption amount and (c, d) CO adsorption amounts on adsorbents as functions of BET surface area at (c) 100 kPa and (d) 10 kPa. ,,,,,− ,,,,,− ,,,− ,,,− ,,− ,− ,,− ,− Solid symbols are for Cu + impregnated adsorbents, and open symbols are for pristine adsorbents.…”