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选取铂铼重整催化剂 ,模拟工业再生过程中催化剂上硫酸根的形成机理 ,制备了含有硫酸根的催化剂样品。以正庚烷为模型化合物 ,在连续加压微反色谱装置上对样品进行活性评价。实验表明 ,硫酸根不但抑制了催化剂的酸性和金属功能 ,同时加快了催化剂的失活速率 ,使芳构化活性与选择性大幅度下降。高铼铂比 (n(Re) / n(Pt)=2 )催化剂对硫酸根的敏感程度大于 n(Re) / n(Pt) =1的催化剂。催化剂表面结构表征表明 ,硫酸根的形成并不导致铂晶粒长大 ,它对催化剂金属功能的抑制是由于部分被还原为硫化氢而使金属过硫化所致 ;硫酸根的形成引起了催化剂上氯含量下降 ,使催化剂表面 L酸强度降低 ,造成催化剂补氯困难 ,但并不破坏载体的结构。
The catalyst for platinum-rhenium reforming was selected to simulate the formation mechanism of sulfate on the catalyst during industrial regeneration, and a catalyst sample containing sulfate was prepared. Using n-heptane as a model compound, the activity of the sample was evaluated on a continuous pressurized microreactor. The experiments show that the sulfate radical not only inhibits the acidity and the metal function of the catalyst, but also accelerates the deactivation rate of the catalyst and greatly reduces the aromatization activity and selectivity. The catalyst with higher rhenium ratio (n (Re) / n (Pt) = 2) is more sensitive to sulfate than the catalyst with n (Re) / n (Pt) = 1. Characterization of the catalyst surface structure shows that the formation of sulfate does not result in the growth of platinum grains and its inhibition of the catalytic metal function is due to the partial over-sulfurization of the metal due to the partial reduction to hydrogen sulfide; the formation of sulfate causes the catalyst Chlorine content decreased, so that the catalyst surface L acid strength decreased, resulting in catalyst chlorine difficult, but does not undermine the structure of the carrier.