Copper and palladium loaded polyol dendrimer-montmorillonite composites as potential adsorbents for CO2 and H2

Intercalation of Na+-montmorillonite (NaMt) by dendrimer H20 and incorporation of palladium (Pd) and copper (Cu) nanoparticles (PdNP and CuNP) resulted in NaMt-H20-Cu and NaMt-H20-Pd materials with affinity towards carbon dioxide (CO2) and hydrogen (H-2). Metal incorporation produced a slight structure compaction due to PdNP and CuNP interactions with clay lattice and dendrimer oxygen atoms. Measurements through CO2 temperature programmed desorption revealed higher CO2 retention capacity for NaMt-H20-Pd but higher hydrogen uptake for NaMt-H20-Cu. The affinity towards hydrogen decreased in the following sequence: NaMt-H20-Cu>NaMt-H20-Pd>NaMt-H20>NaMt, confirming the significant role of the incorporated metals. Hydrogen was found to adsorb almost instantly at ambient temperature and pressure, with easy consecutive release upon slight heating up to 80 degrees C or underforced convection upon strong carrier gas stream. These results demonstrate the occurrence of preponderantly physical hydrogen adsorption, opening promising prospects for the reversible capture of CO2 and hydrogen.