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负载型金属催化剂上甲烷催化部分氧化制合成气反应机理存在着燃烧 重整机理和直接氧化机理之争.如果反应按燃烧 重整机理进行 ,则CO2 是反应的一次产物而CO是二次产物 ;如果反应按直接氧化机理进行 ,则CO是一次产物.本文采用同位素瞬变技术 ,对Ni/Al2O3 催化剂上甲烷部分氧化制合成气反应中CO2 的来源进行了研究 ,结果表明CO2 同CO一样 ,主要来源于催化剂表面NiO与甲烷分解生成的NixC的反应 ,这就有力地证明了反应按直接氧化机理进行.研究结果还表明 ,CO歧化或进一步氧化不是CO2 的主要来源.在实验条件下 ,CO的歧化反应受到热力学平衡的限制 ,转化率很低 ;但反应进行得很快 ,通过该可逆反应气相CO中的C可以与催化剂表面的C进行交换.
The reaction mechanism of partial oxidation of methane to catalytic syngas over supported metal catalyst has the dispute of combustion reforming mechanism and direct oxidation mechanism.If the reaction is carried out according to the mechanism of combustion reforming, then CO2 is the primary product of the reaction and CO is the secondary product. If the reaction proceeds according to the direct oxidation mechanism, CO is a primary product.In this paper, isotope transient technology was used to study the source of CO2 in the partial oxidation of methane to syngas over Ni / Al2O3 catalyst. The results show that CO2 is the same as CO The results show that CO disproportionation or further oxidation is not the main source of CO2. Under the experimental conditions, the reaction of CO The disproportionation reaction is limited by the thermodynamic equilibrium and the conversion rate is very low; however, the reaction proceeds very fast, and C in the CO can be exchanged with the C on the catalyst surface through the reversible reaction.