Structure and Stability of Gas Adsorption Complexes in Periodic Porous Solids as Studied by VTIR Spectroscopy: An Overview

Abstract

Variable-temperature infrared (VTIR) spectroscopy is an instrumental technique that enables structural characterization of gas-solid adsorption complexes by analysis of meaningful vibrational modes, and simultaneous determination of the standard enthalpy change (ΔH0) involved in the gas adsorption process, which allows one to quantify the stability of the corresponding complex. This is achieved by a van’t Hoff analysis of a set of IR spectra recorded over a sufficiently large temperature range. Herein, the use of this versatile spectroscopic technique is demonstrated by reviewing its application to the study of carbon monoxide, carbon dioxide and dinitrogen adsorption on several (alkaline) zeolites, which can be regarded as the archetype of periodic porous solids.

Infrared spectroscopic monitoring of solid-state processes

“…Thus, a huge body of literature about the applications of IR spectroscopy in investigations of processes relevant for understanding the action of porous materials is available and extensively reviewed. [162][163][164][165][166] Here, only a few representative examples will be presented.…”

“…IR spectroscopy is often employed to monitor the occupation of the pores in porous materials, such as metal-organic frameworks (MOF), [167][168][169][170] zeolites, [171][172][173][174] porous carbons 166,[175][176][177] etc. 178 IR spectroscopy can confirm the successful and controllable preparation of C 60 encapsulated inside the pores of zeoliticimidazolate framework 8 (ZIF-8) by solvent-free mechanochemical processes.…”