Oxygen vacancy induced superior catalytic performance in Nd–Ce confined inside carbon nanotubes for N2O–assisted dehydrogenation of ethylbenzene.

[Display omitted] Binary Nd–Ce oxides encapsuled in carbon nanotubes (CNTs) catalysts were synthesized and evaluated in the coupling reaction of ethylbenzene (EB) dehydrogenation and N 2 O decomposition, a promising strategy for styrene (ST) production while mitigating greenhouse gas emissions. The optimized Nd − Ce@CNTs exhibited competitive catalytic performance with an EB conversion of 76 % and a ST selectivity of 71 % compared to Ce@CNTs, highlighting a synergic effect between Ce and Nd in the oxidation dehydrogenation of EB with N 2 O as an oxidant (N 2 O−ODEB). Characterization results indicated that Nd incorporation induced lattice distortions, evident in the expansion or contraction of Ce − O bonds surrounding Nd. Defect densities increased to 1.381, 1.495 and 1.534 for CNTs, Ce@CNTs, and Nd − Ce@CNTs, respectively. This interaction not only facilitated the generation of oxygen vacancies, with a lower formation energy of oxygen vacancy on Nd − Ce@CNTs (2.13 eV) than that on Ce@CNTs (2.49 eV), thereby enhancing oxygen activation and migration, but also optimized the distribution of acid sites, promoting C H activation and EB dehydrogenation. In − situ diffuse reflectance infrared Fourier-transform spectra (DRIFTS) and density functional theory (DFT) calculations revealed that the lower adsorption energy of N 2 O (–1.84 eV) on Nd − Ce@CNTs suggested a more favorable coordinated configuration than Ce@CNTs (–0.90 eV), supported by stronger adsorption intensities at 1270 cm−1 and 1302 cm−1. Furthermore, the elongated N O bond (1.35 Å) of N 2 O on the Nd − Ce@CNTs surface indicated its greater ease of cleavage, providing active oxygen species that collectively contributed to the enhanced catalytic performance in the N 2 O−ODEB. [ABSTRACT FROM AUTHOR]