China’s unique energy reserve structure abundant in coal and scarce in crude oil and natural gas has promoted heavy investment on the research and development of clean coal chemical technologies during last two decades, which has turned China into a heartland for demonstrating, developing, and commercializing virtually every aspect of new coal chemical process technologies. Consequently, breakthroughs in coal gasification, indirect and direct coal-to-liquid (CTL) processes, and methanol-to-olefins (MTO) technologies are catching attention worldwide. Gasification technology for syngas production is the key to high plant availability and economic success for most coal chemical projects. During the past 20 years, both international and Chinese gasifier vendors have reaped great successes in licensing their technologies in the domestic market. Notably, the local vendors have been investing heavily on inventing and improving their technologies to suit the specific requirement of gasifying a variety of coals. The opposed multinozzle gasification technology from East China University of Science and Technology was taken as an example to demonstrate the recent development in this field. The coal chemical industry in China has witnessed several notable achievements in chemical engineering progress, namely CTL (indirect and direct) and MTO. Comprehensive reviews on topics such as catalysis, kinetics, and reactor design and process integration will be provided by leading scientists in related fields with firsthand information to showcase the contributions of Chinese researchers to chemical engineering science and technology.
A study of the promotional effect of potassium on the carburization behavior of a series of spray‐dried precipitated Fe2O3 catalysts (100 Fe, 100 Fe/0.52 K, 100 Fe/1.54 K, and 100 Fe/2.4 K) has been performed by using in situ XRD. The average crystallite size evolution for species such as α‐Fe2O3, Fe3O4, χ‐Fe5C2, and θ‐Fe3C were followed. The potassium promoter clearly inhibits the reduction of α‐Fe2O3 to Fe3O4, where the decreasing binding energy in the Fe 2p3/2, O 1s and K 2p3/2 spectra from X‐ray photoelectron spectroscopy (XPS) suggests an electron density increase in Fe and O upon potassium promotion, leading to the enhanced covalency in the Fe−O bond. In terms of crystallite size during carburization, an optimum potassium loading exists in catalyst 100 Fe/0.52 K, which shows the fastest reduction to Fe3O4 with minimum crystallite sizes of around 7 to 15 nm. Potassium has no clear effect in determining the final crystallite size of χ‐Fe5C2. An arch‐shaped curve in the evolution of crystallite size of the Fe3O4 intermediate was observed, which can be explained by the activation energy difference between the bidirectional steps of the outward oxygen diffusion and the inward carbon diffusion.
As an alternative to noble metal hydrogenation catalysts, pure molybdenum carbide displays unsatisfactory catalytic activity for arene hydrogenation. Precious metals such as palladium, platinum, and gold are widely used as additives to enhance the catalytic activities of molybdenum carbide, which severely limits its potential applications in industry. In this paper, iron-promoted molybdenum carbide was prepared and characterized by various techniques, including in situ XRD, synchrotron-based XPS and TEM. while the influence of Fe addition on catalytic performance for toluene hydrogenation was also studied. The experimental data disclose that a small amount of Fe doping strongly enhances catalytic stability in toluene hydrogenation, but the catalytic performance drops rapidly with higher loading amounts of Fe.
1 January 2021 in Journal of the Serbian Chemical Society
The purpose of this research was to reduce the amount of noble metal palladium catalyst and improve the catalytic performance in the Suzuki?Miyaura cross-coupling reaction, which is the key step in the synthesis of Boscalid. Taking o-bromonitrobenzene and p-chlorophenylboronic acid as raw materials, three kinds of Pd-PEPPSI-IPr catalysts were synthesized and employed in the Suzuki reaction, and then the biaryl product was subjected to reduction and condensation reaction to give Boscalid. Under the optimal reaction conditions, the result showed that the catalytic system exhibits highest catalytic efficiency under aerobic conditions, giving the 2-(4-chlorophenyl)nitrobenzene in over 99 % yield. Moreover, the Pd-PEPPSI-IPrDtBu-An catalyst was minimized to 0.01 mol%. The synthesis process was mild, the post-treatment was simple, and the production cost was reduced, which makes it suitable for industrial production.