CO2 Adsorption by para-Nitroaniline Sulfuric Acid-Derived Porous Carbon Foam

Enrico Andreoli,Andrew Barron

doi:10.3390/c2040025

Enrico Andreoli, Andrew Barron

Open Access

https://doi.org/10.3390/c2040025

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Abstract

The expansion product from the sulfuric acid dehydration of para-nitroaniline has been characterized and studied for CO2 adsorption. The X-ray photoelectron spectroscopy (XPS) characterization of the foam indicates that both N and S contents (15 and 9 wt%, respectively) are comparable to those separately reported for nitrogen- or sulfur-containing porous carbon materials. The analysis of the XPS signals of C1s, O1s, N1s, and S2p reveals the presence of a large number of functional groups and chemical species. The CO2 adsorption capacity of the foam is 7.9 wt% (1.79 mmol/g) at 24.5 °C and 1 atm in 30 min, while the integral molar heat of adsorption is 113.6 kJ/mol, indicative of the fact that chemical reactions characteristic of amine sorbents are observed for this type of carbon foam. The kinetics of adsorption is of pseudo-first-order with an extrapolated activation energy of 18.3 kJ/mol comparable to that of amine-modified nanocarbons. The richness in functionalities of H2SO4-expanded foams represents a valuable and further pursuable approach to porous carbons alternative to KOH-derived activated carbons.

Highlights

There are two general classes of material employed for CO2 separation: physical and chemical sorbents
These materials show high selectivity, their other drawbacks have meant that research has focused on the study of porous carbons (PCs) [6,7], metal-organic frameworks (MOFs) [8,9], microporous zeolites [10], high surface area silica-based amine-modified sorbents [11,12], and crosslinked amine sorbents [13,14,15]
It is known that neither texture nor volume of the foam is affected by the mole ratio of reactants, while the expansion of the foam is dependent on the heating schedule [28]

Summary

Introduction

There are two general classes of material employed for CO2 separation: physical and chemical sorbents. Many commonly used ionic liquids, suitable for high-pressure capture, are expensive and toxic [4], while alkali-metal oxides suffer from deactivation and limited durability [3,5] These materials show high selectivity, their other drawbacks have meant that research has focused on the study of porous carbons (PCs) [6,7], metal-organic frameworks (MOFs) [8,9], microporous zeolites [10], high surface area silica-based amine-modified sorbents [11,12], and crosslinked amine sorbents [13,14,15]. S-doped PC material (NSPC) could offer chemical adsorption of CO2 on porous carbon substrates

Results and Discussion

SO4chemistry

High resolution

Materials and Characterization

CO2 Adsorption

Conclusions