High-efficiency CO 2 capture and separation over N 2 in penta-graphene pores: insights from GCMC and DFT simulations
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High-efficiency CO2 capture and separation over N2 in penta-graphene pores: insights from GCMC and DFT simulations Xiaoqing Lu1,*, Maohuai Wang1, Guanwei Luo2, Sainan Zhou1, Jiahui Wang1, Huili Xin3, Zhaojie Wang1, Siyuan Liu1, and Shuxian Wei3,* 1
School of Materials Science and Engineering, China University of Petroleum, Qingdao 266580, Shandong, People’s Republic of China 2 Qingyang Petrochemical Company of PetroChina, Qingyang 745100, Gansu, People’s Republic of China 3 College of Science, China University of Petroleum, Qingdao 266580, Shandong, People’s Republic of China
Received: 18 May 2020
ABSTRACT
Accepted: 12 August 2020
CO2 capture and separation over N2 in penta-graphene (PG) slit pores (PG-x, x = 7-12) were investigated by using grand canonical Monte Carlo (GCMC) and density functional theory (DFT) simulations. GCMC results showed that PG pores exhibit high-efficiency CO2 capture and separation over N2. The best performing PG-8 exhibited an extraordinary CO2 adsorption capacity of 8.11 mmol/g at 1 bar and 5.56 mmol/g at 0.15 bar, respectively, with a high CO2/N2 selectivity of 69 at 1 bar and 298 K. The relative concentration distribution analyses illustrated that gas molecules were mainly adsorbed nearby PG nanosheet at their equilibrium states. DFT results showed that CO2 had a higher adsorption energy than that of N2 on PG nanosheet, further demonstrating PG pore as a promising material for CO2 capture and separation.
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Springer Science+Business
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Handling Editor: Christopher Blanford.
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https://doi.org/10.1007/s10853-020-05251-9
J Mater Sci
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Introduction The increasing emission of CO2 has caused severe environmental problems including global warming, sea level rise, and climate change [1, 2]. Using solid adsorbents is regarded as an alternative strategy instead of chemical absorption and cryogenic distillation [3] due to its cost-effectiveness, easy regeneration, and high capture capacity for high-efficiency CO2 capture and separation [4–6]. Among various adsorbent materials, graphene and graphene-like nanomaterials have aroused more and more interests owing to their extraordinary properties, such as large surface area, tunable pore size, and easy functionalization [7–10]. Recently, penta-graphene (PG), consisting entirely of pentagons with great energetic, dynamic, thermal, and mechanical stability, has been reported [11].
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Similar to that graphene could be obtained by mechanical exfoliated from highly oriented pyrolytic graphite [12], PG was proposed to be exfoliated from T12-carbon, indicating the technological possibility to obtain PG. It had a negative Poisson
