Acid treated kaolinites (KA) were successively loaded with Zr and Fe, Ni or Co component to control the product distribution and upgrade the tar quality in coal pyrolysis. The structure of the resultant catalysts was characterized and their catalytic performance in the pyrolysis of demineralized low-rank coal and benzyl phenyl ether (BPE), a model compound containing C_al-O bridge bond, were investigated. Results show that the introducing of Zr into the KA can enlarge the hysteresis loop due to the stacking of ZrO₂ particles. The acidities, especially the strong ones, increase as the Zr content is below 8 wt% (KA-8Z). When adding Fe, Ni or Co metals into the KA-8Z, the number of Brønsted acid sites obviously decreases, but Lewis acid sites increase. The maximum BPE conversion of 94.0% occurs for the KA-8Z, further metal-loaded sample promotes the cleavage of C_al-O bond in BPE and the formation of active H radicals from CH₃OH, leading to the increase of BPE conversion. Besides, remarkable enhancement of target monomeric aromatics is observed for the Fe, Ni and Co-loaded samples. Compared with the pyrolysis without catalyst, the tar yield as well as pitch content decrease over the KA-8Z and its metal-modified catalysts. Wherein, Ni-KA-8Z has the highest activity for tar upgrading, leading to the largest increase in the contents of light oil and phenol oil. In-situ pyrolysis by time-of-flight mass spectrometry reveals the enhanced dissociation of weak covalent bonds linked in the coal skeleton over the KA-8Z and Fe, Ni and Co-modified catalysts, resulting in a decrease in the peak temperature for product release. A marked increase in phenols and diphenols confirms a promoted dissociation of ether bond in coal.

酸处理过的高岭石（KA）先后加载Zr和Fe，Ni或Co组分，以控制产品分布并提高煤热解过程中的焦油质量。表征了所得催化剂的结构，并研究了它们在脱盐低阶煤和苄基苯基醚（BPE）（一种含C _a1- O桥键的模型化合物）的热解中的催化性能。结果表明，由于ZrO ₂的堆积，将Zr引入KA可以扩大磁滞回线。粒子。当Zr含量低于8 wt％（KA-8Z）时，酸度（尤其是强酸度）会增加。当将Fe，Ni或Co金属添加到KA-8Z中时，布朗斯台德酸位的数量明显减少，而路易斯酸位增加。KA-8Z的最大BPE转化率为94.0％，进一步的金属负载样品促进了BPE中C _al -O键的裂解以及CH ₃形成活性H自由基OH，导致BPE转化率增加。此外，对于Fe，Ni和Co负载的样品，目标单体芳烃的显着增强。与没有催化剂的热解相比，焦油收率和沥青含量比KA-8Z及其金属改性催化剂要低。其中，Ni-KA-8Z的焦油提质活性最高，导致轻油和酚油含量的增加最大。飞行时间质谱仪进行的原位热解表明，在KA-8Z和Fe，Ni和Co改性催化剂上，煤骨架中弱共价键的解离增强，导致产物的峰值温度降低发布。酚和二酚的明显增加证实了煤中醚键的促进离解。