Structure–Property Correlation of Hierarchically Porous Carbons for Fluorocarbon Adsorption

Abstract

Although traditional commercially available porous carbon–fluorocarbon working pairs have shown promising applicability for adsorption cooling, advancements in engineered carbons may further improve the performance. Moreover, insights into structure–property relationships that target higher sorption capacities within these synthesized carbons may guide such materials’ future design. We utilized hierarchically porous carbons (HPCs), synthesized with colossal microporous and mesoporous content characterized by high surface areas (up to 2689 m2/g) and pore volume values (up to 10.31 cm3/g) toward fluorocarbon R134a adsorption. This unique pore topology leads to exceptional R134a uptake, ∼250 wt %, outperforming the highest uptake carbon material to date, Maxsorb III (∼220 wt %). Material characterizations reveal that the outstanding R134a capacity may be attributed to textural properties and oxygen-terminated functional groups more than graphitization of the material. Most importantly, HPCs are efficiently utilized in a two-bed model chiller device, where the performance shows excellent working capacity (105 wt %, ∼2 times the value of reported carbon materials/R134a). Fluorocarbon adsorption on HPCs also displays fast kinetics (equilibrium time: ∼2 min) mainly driven by physical adsorption (Qst: ∼27 kJ/mol), characteristic of swiftly reversible behavior adsorption–desorption behaviors. This work provides a fundamental understanding of the applicability of HPCs/R134a working pair for adsorption cooling.

Manipulating Pore Topology and Functionality to Promote Fluorocarbon-Based Adsorption Cooling

“…Many similar insights regarding guest sorption in pores can be ascertained from isotherm shapes. Specifically, regarding fluorocarbon sorption in MOFs, solidstate 19 F magic angle spinning NMR of sample cells containing gas-only vs sorbent with gas was able to show distinct/shifted resonance peaks in the observed spectrum. 10 This bulk sorption analysis was performed using relatively heavy and more polarizable R-12 fluorocarbon but can presumably be performed using other lighter fluorocarbons as well.…”

“…Traditionally used sorbent technologies for chiller use include metal salts, silicas, zeolites, and carbons. , These sorbents offer advantages such as material stability for consistent, extended use, and low material cost. However, their limited porosity and low refrigerant affinity result in low sorption and low cooling efficiencies.…”

Polymer Waste Valorization into Advanced Carbon Nanomaterials for Potential Energy and Environment Applications

“…[9] The driving factor for the rising interest in CNMs is their unique features, such as high specific surface area, well-developed porous architecture, high electric conductivity, rich surface chemistry, and excellent thermal stability. Because of these excellent features, CNMs offer a wide range of possible uses (Figure 2), such as adsorbents (for gases, dyes, and heavy metal ions), [8,10,11] pollutant remediation, [12][13][14] adsorption cooling, [15,16] supercapacitor materials, [17][18][19][20] solar cells, [21,22] electrodes in batteries, [23,24] Hydrogen evolution reaction (HER) and Oxygen evolution reaction (OER) catalysts, [25][26][27][28] drug delivery, [29,30] bioimaging and biosensing. [31,32] Waste polymeric materials have rich content of carbon, and thereby can be valorized into various CNMs.…”

“…Among different CNMs, nanoporous AC, graphene, and CNTs exert several distinctive characteristics, including large surface area, huge aspect ratio, well-developed microporous structure, superior mechanical power, high electrical conductance, and electron mobility, which make them ideal for gas adsorption, and energy applications such as supercapacitors and water electrolysis. [15,16,33,34] In this regard, the conversion of polymer wastes into CNMs proves to be a sustainable, environment-friendly, and valuable approach to managing polymer waste. Thus, utilizing polymeric waste derived carbon nanomaterials (PWDCNMs) for CO 2 capture, supercapacitor and water splitting applications provides a capable and ecological strategy for addressing the demanding polymer waste management issue while simultaneously reducing global warming, water pollution, and energy crisis, respectively.…”

Novel catalysts with multivalence copper for organic pollutants removal from wastewater with excellent selectivity and stability in Fenton‐like process under neutral pH conditions

“…Compared with iron-based Fenton-like catalysts, porous frameworks supported copper-based catalysts show better catalytic activity for many catalytic reactions and high •OH yields in Fenton-like reactions at neutral pH values (Da et al, 2019;Shen et al, 2021;Zheng et al, 2019Zheng et al, , 2021. For example, majority of heterogeneous copper catalysts over alumina, polymers, zeolites, and resins have been used for the degradation of aromatic compounds and dyes (Barpaga et al, 2020;Ivanchikova et al, 2017;Li et al, 2020;Zheng et al, 2018Zheng et al, , 2020Zheng, Vemuri, et al, 2017).…”