Improvement in activity for the Zr doped VPO catalyst appears to be a general observation in aldol condensation of methyl acetate and formaldehyde to methyl acrylate. The deactivation behavior significantly differs between VPO and VPO-Zr catalysts. In this work, the deactivation/reactivation behavior and carbon formation in aldol condensation on VPO and VPO-Zr catalysts were investigated. After partial deactivation of the conversion of methyl acetate and formaldehyde to methyl acrylate with a fixed-bed reactor, the deactivated catalysts were fractionated from the reactor. The samples were then analyzed by spectroscopic techniques, gas adsorption measurements and thermogravimetry. The VPO-Zr catalyst showed differences in deactivation/reactivation behavior from the VPO catalyst under same reaction conditions. This finding could be partially ascribed to different coke locations in the deactivated catalysts with varied porosity. The I_V⁴⁺/I_V⁵⁺ ratio of V atom remarkably differed among fresh, used, and refreshed catalysts, which could be a key factor affecting catalyst deactivation. The relations of carbon formation and reaction time were fitted by empirical Voorhies equation over VPO and VPO-Zr catalysts. ¹

Zr掺杂的VPO催化剂活性的提高似乎是乙酸甲酯和甲醛在醛醇缩合到丙烯酸甲酯中的一般观察结果。VPO和VPO-Zr催化剂之间的失活行为明显不同。在这项工作中，研究了在VPO和VPO-Zr催化剂上醛醇缩合的失活/再活化行为和碳的形成。用固定床反应器使乙酸甲酯和甲醛向丙烯酸甲酯的转化部分失活后，从反应器中分馏失活的催化剂。然后通过光谱技术，气体吸附测量和热重分析法对样品进行分析。在相同的反应条件下，VPO-Zr催化剂的失活/再活化行为与VPO催化剂不同。这一发现可以部分归因于失活催化剂中具有不同孔隙率的不同焦炭位置。我在新鲜，使用和更新的催化剂中，V原子的_V ⁴⁺ / I _V ⁵⁺比率显着不同，这可能是影响催化剂失活的关键因素。在VPO和VPO-Zr催化剂上，通过经验Voorhies方程拟合了碳的形成和反应时间的关系。^1个