Both ReO₃ and methyltrioxorhenium combined with alcohol reductants are used for the efficient deoxydehydration of glycerol to allyl alcohol.

Allyl alcohol (AA) was obtained by the deoxydehydration (DODH) of glycerol performed in the presence of a number of Re compounds (oxides, phosphine and halide derivatives) in alcoholic solvent or in neat conditions. Independently of starting Re species, the resulting catalytic process featured a delay time, necessary to start the formation of both AA and an Re-alkoxide precipitate. However, no delay time was detected by operating DODH using a preformed precipitate obtained by either Re source. As a consequence, and based on IR spectral analysis, it was hypothesized that the Re precipitate is the actual catalyst of DODH. The mechanism of DODH catalysis operated by methyltrioxorhenium (MTO) was studied by experimental and theoretical approaches. The results suggest that MTO releases methane with the formation of an Re^VII alkoxide that subsequently aggregates by yielding the precipitate. The Re^VII centre precipitate surface then undergoes reduction by forming Re^V catalytic spots. The calculated kinetics also indicate that the detected latency can be ascribed to the presence of two high barriers, i.e. methane release and Re^VII → Re^V reduction, whereas the downstream processes, i.e. glycation and AA release, are not rate determining.

Poly(methyl methacrylate) (PMMA) is characterized by high CO₂ capture yield under mild pressures and temperatures. A morphological modification of powdery amorphous PMMA (pPMMA) is carried out by electrospinning to increase the surface/volume ratio of the resulting electrospun PMMAs (ePMMAs). This modification improves the kinetics and the capture yields. The rate constants observed for ePMMAs are two to three times higher than those for pPMMA, reaching 90% saturation values within 5–7 s. The amount of sorbed CO₂ is up to eleven times higher for ePMMAs at 1 °C, and the highest difference in captured CO₂ amount is observed at the lowest tested pressure of 1 MPa. The operating life of the ePMMAs shows a 5% yield loss after ten consecutive runs, indicating good durability. Spent electrospun PMMAs after several cycles of CO₂ sorption-desorption can be regenerated by melting and again electrospinning the molten mass, resulting in a CO₂ capture performance that is undistinguishable from that observed with fresh ePMMA. Scanning electron and atomic force microscopies show a reduction in surface roughness after gas exposure, possibly due to the plasticization effect of CO₂. This study shows the potential of electrospun PMMAs as solid sorbents for carbon capture from natural gas or pre-combustion and oxyfuel combustion processes.