Coupling non-thermal plasma with Ni catalysts supported on BETA zeolite for catalytic CO₂ methanation

Abstract

Non-thermal plasma activation promotes CO2 conversion over Ni catalysts supported on BETA zeolite via multiple reaction mechanisms.

Structured Ni@NaA zeolite supported on silicon carbide foam catalysts for catalytic carbon dioxide methanation

“…The mechanisms of catalytic CO 2 methanation over different catalysts have been previously researched by different methods 2,5,42‐45 . In this work, comparative in situ DRIFTS‐MS studies of CO 2 methanation over the catalysts under investigation were further performed to see whether or not the presence of SiC foam might affect the surface reactions.…”

“…The first sets of experiments were performed for the structured catalyst of 15Ni@NaA‐SiC as a function of the reaction temperature. As shown in Figure 7, by ramping the temperature from 30 to 400°C (10% CO 2 + 40% H 2 diluted in Ar), the following surface changes were observed: (a) the intensity of the IR band related to hydroxyl groups (at 1,650 cm −1 and 3,500–3,800 cm −1 , corresponding to the adsorbed water molecules and surface hydroxyl groups in NaA) diminished progressively; (b) the IR band at 2,349 cm −1 (which is related to the gas phase CO 2 , shaded by the green rectangle) disappeared gradually, indicating the consumption of CO 2 due to the reaction over the catalyst; (c) the IR band at 1,566 cm −1 (which could be attributed to monodentate carbonates adsorbed on extra frame‐work aluminium of NaA zeolite or Ni 0 species 43 ) appeared progressively at 100–300°C, then diminished gradually by increasing the temperature up to 400°C; (d) the C‐H vibration of CH x species (which is characterized by the IR band at 3,000 cm −1 , shaded by the blue rectangle) appeared gradually at temperatures higher than 300°C 2 . Additionally, in situ DRIFT study of the 15Ni@NaA catalyst in the catalysis was also carried out (Figure S9), showing the comparable spectra to the structured catalysts under the same conditions.…”

“…82%), being the primary reasons for the serious global warming and climate change issues 1 . Therefore, many efforts have been made recently to develop highly efficient CO 2 capture and utilization (CCU) technologies for reducing and converting CO 2 emissions, fighting against the urgent environmental issues 2 . The power‐to‐gas (P2G) process is an energy storage and conversion technology that can convert the surplus sustainable energy into gas fuel (i.e., hydrogen, H 2 ) effectively, which can be subsequently used for CO 2 conversion (to methane) 3‐8 .…”

“…200–750°C) are normally required to activate the catalyst to enable the hydrogenation of CO 2 11 . In addition, CO 2 methanation is highly exothermic (Equation ) and the development of local hotspots is common along the catalytic packed bed, being one of the main reasons for catalyst sintering and deactivation 2 . Moreover, conventional fixed bed reactors with packed catalyst pellets normally suffer from poor heat transfer and insufficient heat dissipation, which are likely to result in thermal runaway, and thus associated deactivation and safety issues 12,13 …”

Nonthermal plasma (NTP) activated metal–organic frameworks (MOFs) catalyst for catalytic CO2 hydrogenation

“…Nonthermal plasma (NTP) is a promising alternative to the conventional thermal system for activating catalysts at comparatively low temperatures (<200 C), enabling various challenging reactions. 12,13 Specifically, NTP activation has been demonstrated as an efficient technique for promoting WGS and CH 4 oxidation, without an external heat source. [14][15][16] Recently, catalytic CO 2 hydrogenation was also enabled by NTP at low temperatures of <150 C. 13,17,18 For instance, hydrogenation of CO 2 to CH 4 over Ni-…”