The new finding is published in Science Advances.
An ECNU research team led by Prof. Lu Yong with the Shanghai Key Lab of Green Chemistry and Chemical Processes identified a breakthrough in new technology and development for the exploitation of shale gas and coalbed methane resources in China. His work in MnTiO3-driven low-temperature oxidative coupling of methane over TiO2-induced Mn2O3-Na2WO4/SiO2 catalyst is an intriguing find for petrochemistry.
The work by doctoral student Wang Pengwei, associate researcher Zhao Guofeng, Prof. Lu Yong and Zhao Guofeng was published inScience Advances journal, which revealed their new findings in MnTiO3-drivenlow-temperature oxidative coupling of methane over TiO2-doped Mn2O3-Na2WO4/SiO2catalyst.
Prof. Lu Yong (center) and Zhao Guofeng (right) and Wang Pengwei (left) work in the lab.
Methane is a clean and cheap hydrocarbon resource that can found in natural gas, shale gas, and gas hydrates. It can also be produced from renewable biomass energy fuels, offering more sustainability than crude oil deposits.
In this context, the depletion of global crude oil has stimulated collective efforts to convert methane into more efficient chemical compositions and transportable fuels. As the main constituent of natural gas, the amount of methane at a country’s disposal can actually measure thestrength of it’s petroleum industry.
The Mn2+-to-Mn3+ transition rate and proposed catalytic recycle for OCM process.
In modern petrochemistry, large-scale conversion from methane to olefins has become a common chemical reaction used by scientists to initiate natural gas. This processfollows an indirect route, first converting the methane to methanol which results in the production of olefins.
Oxidative coupling of methane (OCM) is a more likely method for the direct conversion of methane to ethene and ethane (C2 products). Among the catalysts reported previously, Mn2O3-Na2WO4/SiO2 showed the highest rates of conversion and selectivity, though at 800° to 900°Crepresents a substantial challenge for commercial endeavors.
Prof. Lu Yong (center) and Zhao Guofeng (left) and Wang Pengwei (right)
Inspired by the obtained insight into the MnTiO3-enhanced low-temperature catalysis for the OCM process, the ECNU researchers reported a TiO2-induced Mn2O3-Na2WO4/SiO2 catalyst that coverted 26% OCM and 76% C2-C3 selectivity at 720°C.
MnTiO3 triggers the low-temperature Mn2+-Mn3+ cycle for O2 activation while working in synergy with Na2WO4 to select and convert methane to C2-C3. They also prepared a practical Mn2O3-TiO2-Na2WO4/SiO2 catalyst in a ball mill - a grinder employed to grind and blend materials for use in mineral processing. This method can transform the catalyst into MnTiO3-Na2WO4/SiO2, yielding 22% conversion and 62% selectivity at 650°C.
The study inspired more attempts to understand the chemistry of MnTiO3-governed low-temperature activity, which might lead to an increased commercial exploitation to find a more effective low-temperature catalyst. This has the potential to facilitate proper low-temperature activity and selectivity in combination with the stable OCM process for optimal results.