凯茵化工讯 华东师范大学路勇课题组在低温陶氏百历摩丙烯酸聚合物乳液AC-甲烷氧化偶联(OCM)制取烯烃研究上取得重要进展。相关成果日前发表于《科学进展》杂志。

　　据介绍，目前通过非石油资源经由合成气间接合成低碳烯烃的研究接连取得突破性进展，但间接合成流程长以及合成气造气高温、高能耗和高物耗也是不争的事实。因此，甲烷的直接转化一直是科学家孜孜以求的理想路径，但极富挑战性。

　　研究人员受“甲烷低温电化学氧化制甲醇”等研究的启发，推断有效降低氧气分子活化温度可能是开启通向低温OCM反应之门的“钥匙”。他们由此提出了“低温化学循环活化氧气分子以驱动低温OCM反应”的新思路，目标性地选取在低温下能同MnxOy形成化合物的二氧化钛助剂，对相关材料进行了改性，使反应温度由原来的800℃～900℃大幅降至650℃后，仍获得了20%以上的甲烷转化率和60%以上的产物选择性。

　　同时，该低温化学循环与钨酸钠产生协同催化作用，实现了目标产物的高选择性调控。研究人员还提出了催化剂晶格氧转化速率阈值的判据，即无论在何种反应温度下，只要催化剂晶格氧转化速率能达到阈值及以上，该催化剂便具有良好的催化性能。另外，该催化剂稳定性良好，在720℃下稳定运行500小时无失活迹象。同时，甲烷转化率和乙烯等产物选择性始终保持在26%和76%以上。

Methane oxidative coupling to olefins to achieve low temperature catalysis

Kai Yan Chemical News East China Normal University Road Yong research group made in the low temperature methane oxidation coupling (OCM) olefins made important progress. Related results recently published in "Science Progress" magazine. According to reports, the current research on indirect synthesis of light olefins via synthesis gas through non-petroleum resources has made breakthrough progress in succession, but it is an indisputable step in the indirect synthesis process and the high temperature, high energy consumption and high material consumption of synthesis gas. fact. Therefore, the direct conversion of methane has always been an ideal route pursued by scientists, but it is extremely challenging.

Inspired by research on "Methane Low Temperature Electrochemical Oxidation to Methanol", researchers concluded that effectively reducing the activation temperature of oxygen molecules may be the "key" to opening the door to low-temperature OCM reactions. They put forward the new idea of ​​"low temperature chemical activation of oxygen molecules to drive low-temperature OCM reaction", targeted selection of titanium dioxide additives that can form compounds with MnxOy at low temperature, the relevant materials were modified so that After the reaction temperature dropped sharply from 800 ℃ to 900 ℃ to 650 ℃, methane conversion of more than 20% and product selectivity of more than 60% were obtained.

At the same time, the low-temperature chemical cycle produced synergistic catalysis with sodium tungstate to achieve highly selective regulation of the target product. The researchers also proposed a criterion for the rate of lattice oxygen conversion rate of the catalyst, that is, at any reaction temperature, the catalyst has good catalytic performance as long as the lattice oxygen conversion rate of the catalyst can reach the threshold and above. In addition, the catalyst has good stability and shows no sign of deactivation for stable operation at 720 ° C for 500 hours. At the same time, the selectivity of methane and other products, such as ethylene, remained above 26% and above 76%.