Catalytic behavior of a ZnO/TiO₂composite in the synthesis of polycarbonate diol

Abstract

TiO2 loaded with zinc oxide (ZnO/TiO2) catalysts were prepared and showed good catalytic performance of the transesterification of diphenyl carbonate (DPC) with 1,4-butanediol (BDO) to produce polycarbonate diol (PCDL).

Magnetic hollow micro-sized nanoaggregates for synergistically accelerating PET glycolysis

“…The desorption peaks of NH 3 -TPD patterns at about 400 °C with wider temperature windows correspond to strongly acidic sites, and the peaks at low temperatures correspond to weak (below 200 °C) and medium strength acidic sites (200-350 °C). 36,[47][48][49] The NH 3 -TPD study confirms that the HMNAs composed of ZnO NPs under 10 nm have a strongly acidic site at 395 °C. Although the peak of Fe and the peak at 1539 cm −1 is attributed to the Brønsted acid sites.…”

“…The desorption peaks of NH 3 -TPD patterns at about 400 °C with wider temperature windows correspond to strongly acidic sites, and the peaks at low temperatures correspond to weak (below 200 °C) and medium strength acidic sites (200–350 °C). 36,47–49 The NH 3 -TPD study confirms that the HMNAs composed of ZnO NPs under 10 nm have a strongly acidic site at 395 °C. Although the peak of Fe 3 O 4 NPs at 272 °C indicates a high content of medium-strength acidic sites, the desorption peaks of ZnO–Fe 3 O 4 HMNAs in the low-temperature range change slightly, revealing that Fe 3 O 4 NPs have little effect on the acidic sites of the composite HMNAs.…”

“…38,50 The ratio of Brønsted to Lewis acid sites in HMNAs was calculated to be 0.08, indicating that the ZnO–Fe 3 O 4 HMNAs are Lewis acid-based catalysts. 47…”

“…38,50 The ratio of Brønsted to Lewis acid sites in HMNAs was calculated to be 0.08, indicating that the ZnO-Fe 3 O 4 HMNAs are Lewis acid-based catalysts. 47 Fig. 7 shows that the acidity of glycolysis catalysts is positively related to their degradation efficiency in Fig.…”