PR-CO2

High pressure photoreduction of CO2
inside inorganic and metal organic porous materials

A project funded by the Italian MUR, within the PRIN-PNRR call 2022

People Involved

POLIMI (Politecnico di Milano): Prof. Piero Macchi (unit leader and project principal investigator); Prof. Javier Marti-Rujas; Dr. Anindita Goswani (post doc); Dr. Selene Varliero (PhD Student, thesis defended); Ms. Yidian Wang (PhD student); Dr. Stefano Elli (PhD Student, thesis defended).

UNIFI (University of Florence): Prof. Roberto Bini (unit leader); Prof. Gianni Cardini; Dr. Gianni Pietraperzia; Ms. Selene Berni (PhD Student); Ms. Milo Agati (PhD Student).

CNR (National Research Council – National Institute of optics): Dr. Mario Santoro (unit leader); Dr. Samuele Fanetti; Dr. Demetrio Scelta; Dr. Matteo Ceppatelli

Laboratories involved

UNIFI:The European Laboratory for Non-linear Spectroscopy (LENS) for spectroscopic and diffraction studies

POLIMI: NeXtGAME (Next Generation Advanced Materials) for X-ray diffraction studies

 

The porous matrices are materials like inorganic zeolites and metal organic frameworks. Both have been already proposed and tested for photoreduction, but without applying compression. On the other hand, it is well known that solids under high pressure may undergo chemical reactions more easily than at ambient conditions, mainly because of the significant reduction of energetic barriers along the reaction paths. Thus, combining porous materials and high pressure is expected to improve the reaction yields making low-cost catalysts more efficient for the photoreduction process. This project deals with alternative and unprecedented solutions for the transformation of CO2 into valuable chemicals and fuels. The reduction of CO2 is a necessary step for its removal from the atmosphere or from emissions of exhaust gasses while producing appealing energetic materials. The hypothesis to test in this study is that the photo-chemical reduction of CO2 can be improved if the reaction occurs in porous matrices subjected to compression.The porous matrices are materials like inorganic zeolites and metal organic frameworks. Both have been already proposed and tested for photoreduction, but without applying compression. On the other hand, it is well known that solids under high pressure may undergo chemical reactions more easily than at ambient conditions, mainly because of the significant reduction of energetic barriers along the reaction paths. The hypothesis will be validated by measuring X-ray diffraction and optical spectroscopy on a series of selected materials, compressed at medium (i.e. kbar regime) or very high pressure (i.e., between 1 and tens of GPa) with simultaneous irradiation in the visible and UV spectral region. The selection of zeolites and MOFs will be assisted by theoretical calculations carried out to predict the high pressure behavior and the improved efficiency under compression.

The Diamond Anvil cell

(a) schematic view of a screw-driven diamond anvil cell (courtesy of Dr. Arianna Lanza, PhD Thesis, University of Bern ©); (b) modified Merril-Basset DACs

(a) Schematic view of a gas-membrane DAC (courtesy of Dr. Arianna Lanza, PhD Thesis University of Bern ©); (b) A gas membrane DAC

The Cryoloading Technique

The cryoloading in DACs (LENS laboratory, ©)
The cryo-loading in DAC (LENS laboratory, ©)
a DAC containing the mixture inserted in the vacuum chamber of the FTIR set-up. The green laser probes the internal pressure via the ruby fluorescence method (LENS laboratory, ©)

typical gold protected gasket for the DAC (LENS laboratory, ©)
typical CO2/H2O pristine mixture to be loaded together with zelolites or mofs in DAC (LENS laboratory, ©)
A cold flux of CO2 and water is frozen in the sample compartment of a DAC, where also zeolites are inserted (video produced by LENS laboratory, ©)

The Single Crystal / Powder X-ray Diffraction Technique

The typical set up for single crystal or powder X-ray diffraction
The measurement of pressure by means of Ruby fluorescence

Results

Publications

Santoro, M. et al.
Simultaneous H2O and CO2 High-Pressure Insertion in Zeolites and Metal-organic Frameworks
to be submitted

Goswami, A. Elli, S.; Macchi, P.
High pressure behavior of PCN-250
to be submitted

Wang, Y.; Macchi, P.
Impact of linker defects on the dielectric properties of the Metal-organic framework HKUST-1: Insights from Molecular Dynamics Simulations
ACS Applied Materials & Interfaces, 2026  under revision

Macchi, P.
Polarizabilities of Atoms in Molecules: Choice of the Partitioning Scheme and Applications for Secondary Interactions
Molecules, 2025,30, 4137
https://www.mdpi.com/1420-3049/30/20/4137

Berni, S.; Scelta, D.; Romi, S.; Fanetti, S.; Alabarse, F.;Wehinger, B.; Bini, R.
Understanding the formation mechanism of crystalline hydrated polymorphs of carbonic acid from CO2 clathrate hydrate
Chem. Sci., 2025, 16, 22769-22780.
https://pubs.rsc.org/en/content/articlehtml/2025/sc/d5sc02241j

Berni, S.; Scelta, D.; Romi, S.; Fanetti, S.; Alabarse, F.; Pagliai M.; Bini, R.  
Exploring High-Pressure Polymorphism in Carbonic Acid through Direct Synthesis from Carbon Dioxide Clathrate Hydrate
Angew. Chem. 2024, 63, e202403953. 
https://onlinelibrary.wiley.com/doi/10.1002/anie.202403953