Porous Aromatic Melamine Schiff Bases as Highly Efficient Media for Carbon Dioxide Storage

Abstract

High energy demand has led to excessive fuel consumption and high-concentration CO2 production. CO2 release causes serious environmental problems such as the rise in the Earth’s temperature, leading to global warming. Thus, chemical industries are under severe pressure to provide a solution to the problems associated with fuel consumption and to reduce CO2 emission at the source. To this effect, herein, four highly porous aromatic Schiff bases derived from melamine were investigated as potential media for CO2 capture. Since these Schiff bases are highly aromatic, porous, and have a high content of heteroatoms (nitrogen and oxygen), they can serve as CO2 storage media. The surface morphology of the Schiff bases was investigated through field emission scanning electron microscopy, and their physical properties were determined by gas adsorption experiments. The Schiff bases had a pore volume of 0.005–0.036 cm3/g, an average pore diameter of 1.69–3.363 nm, and a small Brunauer–Emmett–Teller surface area (5.2–11.6 m2/g). The Schiff bases showed remarkable CO2 uptake (up to 2.33 mmol/g; 10.0 wt%) at 323 K and 40 bars. The Schiff base containing the 4-nitrophenyl substituent was the most efficient medium for CO2 adsorption and, therefore, can be used as a gas sorbent.

Synthesis and Use of Valsartan Metal Complexes as Media for Carbon Dioxide Storage

“…Additionally, Sn metal is a stronger Lewis acid than the other two metals, which would promote the electrostatic interaction with carbon dioxide. The efficiency of the synthesized metal complexes as carbon capture media is comparable with those reported for some polyphosphates and telmisartan tin complexes, but lower than those reported for melamine Schiff bases and highly aromatic polyphosphates [35][36][37][38].…”

“…In the current study, the synthesis of three valsartan metal complexes and their use as media for capturing CO 2 were investigated. Recently, we showed that various materials can be used as efficient media for CO 2 capture [35][36][37][38].…”

Synthesis and use of carvedilol metal complexes as carbon dioxide storage media

“…The Ni(II) complex has a high charge density compared to the others [50]. Schiff bases containing melamine showed good CO 2 uptake (up to 10 wt%), however, they have small surface area (up to 11.6 m 2 /g) [30]. Similarly, porous polyphosphates containing benzidine units in their skeleton have small surface area (up to 30 m 2 /g), but adsorbed CO 2 efficiently (up to 14 wt%) [36].…”

“…However, the POPs synthetic procedures still need optimization and to be simplified [28]. Recently, various porous materials have been designed, synthesized, and used as gas storage media [29][30][31][32][33][34][35][36][37][38][39]. Similarly, covalent organic frameworks (COFs) are nanoporous materials that have strong covalent bonds and can be used in gas adsorption and separation [40].…”

New Porous Silicon-Containing Organic Polymers: Synthesis and Carbon Dioxide Uptake

“…In this regard, our group has recently designed, synthesized, and examined the application of various materials as gas storage media [38][39][40][41][42][43]. Herein, we synthesized a series of new polymeric materials that contain silicon and a Schiff base moiety to investigate their properties and applicability as CO 2 storage media.…”