02345nas a2200253   4500008004100000022001400041245011300055210006900168260000900237300001600246490000700262520142600269653003101695653004101726653003601767653002201803653003201825100001801857700001901875700002501894700001901919700002201938856013101960       2025                        eng d  a2168-048500aAdditive-free, selective synthesis of N-heteroaromatics using morphology-engineered hollow CeO2 nanocatalyst0 aAdditivefree selective synthesis of Nheteroaromatics using morph  cDEC   a21266-212760 v133 a<p>
	We developed a highly efficient, shape-controlled CeO2 nanocatalyst for synthesizing N-heteroaromatics via an aerobic dehydrogenation approach, operating at mild reaction conditions without needing toxic acid/base additives. Different morphologies of CeO2, namely, hollow nanospheres, nanorods, and irregularly shaped nanoparticles, were synthesized, as confirmed by electron microscopy analysis. The CeO2 hollow nanosphere catalyst (CeO2-HNS) exhibited unique features, such as abundant acid-base sites, larger-sized voids, and surface oxygen vacancies. These characteristics are found to be crucial for the additive-free oxidative dehydrogenation of saturated N-heterocycles over the CeO2-HNS catalyst, resulting in 98% conversion of 1,2,3,4-tetrahydroquinoline with 100% quinoline product selectivity. The versatility of this approach was further demonstrated by the successful aerobic dehydrogenation of a broad range of saturated N-heterocycles, affording N-heteroaromatics in good to excellent yields. Furthermore, the CeO2-HNS nanocatalyst showed exceptional reusability over six cycles without requiring a regeneration step, such as high-temperature calcination treatment. The structural and morphological stability of the CeO2-HNS catalyst, along with reaction scalability and favorable green chemistry metrics, emphasized the practical viability of the CeO2-HNS catalyst for industrial applications.</p>
10aacid-base and defect sites10aadditive-free aerobicdehydrogenation10aCeO2 hollow nanosphere catalyst10aN-heteroaromatics10areusability and scalability1 aSingh, Nittan1 aSwapna, Bhattu1 aBalu, Alina, Mariana1 aBhatte, Kushal1 aSudarsanam, Putla  uhttps://library.ncl.res.in/content/additive-free-selective-synthesis-n-heteroaromatics-using-morphology-engineered-hollow-ceo2