Catalytic characteristics of NASICON-type phosphates with rare earth elements in ethanol conversion

The study is dedicated to the investigation of the catalytic properties of M0.333+ Ti2(PO4)3 (M − La, Sm, Dy) phosphates in ethanol conversion reactions. The powder samples of the NASICON-type phosphates were synthesized by the Pechini technique. Their phase purity and structure characterization were performed using XRD, IR spectroscopy, SEM, BET and BJH methods. Structural data indicated that the transition from La to Dy was accompanied by a decrease in M − O bond lengths, which is compensated by longer neighboring Ti–O bonds, ultimately leading to greater distortion of the surrounding octahedra. The catalytic activity of M0.33Ti2(PO4)3 (M − La, Sm, Dy) phosphates has been studied in ethanol reforming reactions in the temperature range of 240–400 °C. The regularities of changes in the catalytic properties in the La→Sm→Dy series have been traced. The selectivity of ethanol conversion was found to depend on the phosphate composition. The best alcohol conversion was achieved on Dy-phosphate at 400 °C with an ethylene selectivity of 66 %. © 2025 Elsevier Masson SAS