有序介孔炭负载Pt-MoOx催化剂的制备及其催化甲基环己烷脱氢性能

摘要/Abstract

摘要： 以有序介孔炭（CMK-3）作为载体，采用原子层沉积技术制备出催化剂yPt/CMK-3及MoO_x助剂调控催化剂yPt-zMoO_x/CMK-3（y、z分别为Pt和MoO_x的沉积循环次数），研究了沉积循环次数对Pt金属分散度和催化剂甲基环己烷脱氢性能的影响。结果表明，适中的Pt分散度和适量原子级分散的MoO_x助剂能显著提升Pt基催化剂的性能。与10Pt/CMK-3相比，10Pt-1MoO_x/CMK-3催化剂上的脱氢速率（单位时间内单位质量Pt产生H₂的物质的量）从79.02 mol/(g.h)提高至97.88 mol/(g.h)，甲基环己烷转化率由71%提高到91%。MoO_x助剂加入对Pt颗粒分散度影响较小，主要提高了Pt表面电子密度，降低了催化剂的起活温度。此外，MoO_x助剂还通过氢溢流促进H₂在催化剂表面的脱附，从而提高H₂产率。

关键词: 甲基环己烷, 有机液态储氢载体, 脱氢催化剂, 助剂, 有序介孔碳

Abstract: Using ordered mesoporous carbon (CMK-3) as a carrier, yPt/CMK-3 and MoO_x additive-modulated catalyst yPt-zMoO_x/CMK-3 (y and z are the number of deposition cycles of Pt and MoO_x, respectively) were prepared by atomic layer deposition technology. The impact of the number of deposition cycles on the dispersion of the Pt metal and the catalytic performance for the dehydrogenation of methylcyclohexane was studied. The results showed that optimal Pt dispersion and an appropriate amount of atomically dispersed MoO_x additives could significantly improved the performance of Pt-based catalysts. Compared with 10Pt/CMK-3, the dehydrogenation rate (amount of H₂ produced per unit mass of Pt per unit time) on the catalyst 10Pt-1MoO_x/CMK-3 increased from 79.02 mol/(g.h) to 97.88 mol/(g.h), and the methylcyclohexane conversion rate increased from 71% to 91%. The addition of MoO_x additive had little effect on the dispersion of Pt nanoparticles, mainly increased the electron density on the Pt surface and decreased the activation temperature of catalyst. In addition, the MoO_x additives can promote the desorption of H₂ on the catalyst surface through hydrogen overflow, thus increasing the yield of H₂. The research provides a theoretical basis for the design of efficient methylcyclohexane dehydrogenation catalysts.

Key words: methylcyclohexane, organic liquid hydrogen storage carrier, dehydrogenation catalyst, additive, ordered mesoporous carbon

王森孟繁春李卓杨慧敏代晓敏白靖许云华覃勇张斌. 有序介孔炭负载Pt-MoOx催化剂的制备及其催化甲基环己烷脱氢性能[J]. 石油炼制与化工, 2024, 55(9): 33-41.

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