A series of chromium oxides (CrO x ) were prepared using the sol−gel method for the oxidative dehydrogenation of propane into propene (ODHP). After calcination at temperatures ranging from 300 °C to 600 °C, the obtained nanopowders were comprehensively characterized. X-ray diffraction (XRD) results showed an increase in crystallite size with annealing temperature, whereas Brunauer−Emmett−Teller (BET) analysis disclosed a decreasing tendency of specific surface area. Scanning electron microscopy (SEM) results disclosed spherical and smooth shapes with an agglomeration of small fine particles. X-ray photoelectron spectroscopy (XPS) deconvolution revealed a decrement in lattice oxygen, O Lat /O Ads , and Cr 6+ /Cr 3+ with annealing temperature. Raman and ultraviolet−visible light (UV-vis) spectra reported the presence of isolated and polymeric Cr 6+ oxides and the increment of the bandgap energy with the increase of the calcination temperature. Cr-300 exhibited the best catalytic activity due to the smallest crystallite grain size and bandgap energy, the highest O Lat /O Ads , Cr 6+ /Cr 3+ , and O Lat with the largest surface specific area. Furthermore, after a stability test of 100 h, all catalysts maintained >90% propane conversion, and Cr-300 was the most stable. The DFT calculations revealed that the Cr−O site is the leading active site in the promotion of ODHP. The high stability and performance of Cr-300 catalyst regarding ODHP could pave the way for further industrial applications.

Cerium oxide nanopowder (CeOx) was prepared using the sol–gel method for the catalytic oxidation of N, N-dimethylformamide (DMF). The phase, specific surface area, morphology, ionic states, and redox properties of the obtained nanocatalyst were systematically characterized using XRD, BET, TEM, EDS, XPS, H2-TPR, and O2-TPO techniques. The results showed that the catalyst had a good crystal structure and spherelike morphology with the aggregation of uniform small grain size. The catalyst showed the presence of more adsorbed oxygen on the catalyst surface. XPS and H2-TPR have confirmed the reduction of Ce4+ species to Ce3+ species. O2-TPR proved the reoxidability of CeOx, playing a key role during DMF oxidation. The catalyst had a reaction rate of 1.44 mol g−1cat s−1 and apparent activation energy of 33.30 ± 3 kJ mol−1. The catalytic performance showed ~82 ± 2% DMF oxidation at 400 °C. This work’s overall results demonstrated that reducing Ce4+ to Ce3+ and increasing the amount of adsorbed oxygen provided more suitable active sites for DMF oxidation. Additionally, the catalyst was thermally stable (~86%) after 100 h time-on-stream DMF conversion, which could be a potential catalyst for industrial applications.