Ni Supported on LaFeO3 Perovskites for Methane Steam Reforming: On the Promotional Effects of Plasma Treatment in H2–Ar Atmosphere

A review of the advances in catalyst modification using nonthermal plasma: Process, Mechanism and Applications

With the continuous development of catalytic processes in chemistry, biology, organic synthesis, energy generation and many other fields, the design of catalysts with novel properties has become a new paradigm in both science and industry. Nonthermal plasma has aroused extensive interest in the synthesis and modification of catalysts. An increasing number of researchers are using plasma for the modification of target catalysts, such as modifying the dispersion of active sites, regulating electronic properties, enhancing metal-support interactions, and changing the morphology. Plasma provides an alternative choice for catalysts in the modification process of oxidation, reduction, etching, coating, and doping and is especially helpful for unfavourable thermodynamic processes or heat-sensitive reactions. This review focuses on the following points: (i) the fundamentals behind the nonthermal plasma modification of catalysts; (ii) the latest research progress on the application of plasma modified catalysts; and (iii) main challenges in the field and a vision for future development.

Study on the monolayer dispersion behavior of SnO2 on ZSM-5 for NOx-SCR by C3H6: the remarkable promotional effects of air plasma treatment

Aiming to fabricate more practical catalysts for NO_x-SCR with C₃H₆, SnO₂/ZSM-5 having different SnO₂ loadings was prepared and treated with DBD air plasma. The dispersion of SnO₂ on the H-ZSM-5 support and their interactions were investigated with both experimental methods and DFT calculations. SnO₂ displays evident monolayer dispersion behavior, getting a threshold of 0.271 mmol 100 m^-2 support. Plasma treatment improves significantly the SnO₂ dispersion, hence amplifying the monolayer dispersion threshold to 0.380 mmol 100 m^-2. XPS and DFT calculations have testified that plasma treatment strengthens strongly the SnO₂-ZSM-5 support interaction, mainly through donating electrons from Sn⁴⁺ to Al³⁺ in the support, thus improving the dispersion of SnO₂ at the same loadings. Consequently, the catalytic performance is remarkably improved because of the generation of more abundant surface acid sites and superoxide species devoted to the reaction. The sample having a SnO₂ loading near the monolayer dispersion threshold shows the optimal activity in the corresponding catalyst series, demonstrating an evident threshold effect. Over SnO₂/ZSM-5, the reaction goes through a Langmuir-Hinshelwood pathway, involving the adsorption and activation of both NO and C₃H₆ molecules. Surface mono-dentate/bridged-nitrate and carbonate species are the main reaction intermediates.

Dehydrogenation of formic acid over Pd/C catalysts: insight into the cold plasma treatment

Non-thermal plasma treatment has great potential to open a fast and green route for controllable synthesis of highly active supported metal catalysts.