A key issue in attaining highly efficient supported catalysts for the hydrogenation of unsaturated polymers arises from the entanglement between the number of exposed active sites and the severe internal mass transfer limitation caused by their large molecular size. Hence, an ultrasmall N-doped carbon nanosphere with Ni NPs and CQDs embedded (Ni-CQDs/NCNs) was reasonably constructed by low-temperature (400 °C) pyrolysis of the precursor CQDs@Nano-Ni-ZIFs. As-prepared Ni-CQDs/NCNs exhibited superior catalytic activity to a commercial 10% Pd/C catalyst in petroleum resin hydrogenation under a low temperature of 150 °C, which is 100 and 60 °C lower than that of previously reported Ni- and Pd-based catalysts, respectively. The excellent catalytic activity of Ni-CQDs/NCNs mainly contributes to the following factors: first, its ultrasmall structure (ca. 50 nm) eliminates the internal mass transfer limitation; second, the CQDs and N-doped carbon matrix stabilize the 53.1 wt % high-loading Ni NPs at a small size of 5.6 nm, providing abundant active sites; and third, the electronic regulation of N-doped carbon enhances the intrinsic activity of Ni, which was revealed by the experiments and DFT calculations. Besides, Ni-CQDs/NCNs exhibits long-term stability and appreciable magnetic separation performance, making it a considerable candidate for industrial application. This work not only offers a facile approach to prepare nano MOF-derived catalysts but also gives helpful instruction to the rational design of heterogeneous catalysts for the reaction involving large molecules.

Pyrolysis behavior of resins is essential for their high-temperature application. Herein, the high-temperature stability and pyrolysis kinetics and mechanism of rosin glyceride (RGE), hydrogenated rosin glyceride (HRGE), C9 petro-based resin (C9PR), and hydrogenated C9 petro-based resin (HC9PR) under a nonoxidizing atmosphere were investigated by thermogravimetry coupled with Fourier transform infrared spectrometry or mass spectrometry (TG−FTIR/ MS) techniques. Friedman and Starink methods as well as reaction-order and truncated Sestak−Berggren models were used to evaluate kinetic and thermodynamic parameters, and results indicated that f(α) = (1 − α) n was the most probable pyrolysis mechanism for different resins. In addition, the average activation energies for pyrolysis of RGE, HRGE, C9PR, and HC9PR obtained by the Starink method were 188. 97, 170.95, 159.69, and 151.66 kJ/mol, respectively, suggesting that bio-based resins exhibited better high-temperature stability than cycloaliphatic or aromatic petro-based resins thanks to their unique tricyclic phenanthrene structures, and the high-temperature stability of resins mildly would decrease after hydromodification due to the cracking of saturated bonds, which was well supported by TG−FTIR/MS analyses. Possible pyrolysis pathways were proposed.

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