Abstract
High Resolution Image Download MS PowerPoint Slide Dry reforming of methane (DRM) was investigated using Ni–M oxide catalysts prepared by solution combustion synthesis (SCS) and compared with Ni/α-Al 2 O 3 synthesized by impregnation. According to X-ray diffraction, fresh oxide Ni–La and Ni–Ce catalysts displayed low crystallinity, which was improved after DRM, accompanied by the appearance of metallic Ni. Ni–Ce–Al and Ni–La–Al catalysts formed, respectively, CeAlO 3 and LaAlO 3 phases during the reaction. For studied catalysts featuring low surface areas ranging from 3 to 12 m 2 /g, the average metal particle sizes were 12–32 nm according to transmission electron microscopy, with the particles growing larger with time-on-stream (TOS) apart from Ni–α-Al 2 O 3 . DRM tests were conducted for different TOSs, demonstrating that the highest CH 4 transformation rate was concomitant with the highest deactivation rate during 30 min of time-on-stream. The most stable performance in temperature stability experiments was demonstrated by the Ni–Ce–Al catalyst, for which, similar to other catalysts, the H 2 /CO ratio remained close to unity. In long-term stability tests, the Ni–Ce–Al catalyst displayed a 3.1-fold higher turnover frequency (TOF) compared with Ni–α-Al 2 O 3, with no significant deactivation. The TOF values were comparable to the literature, highlighting the potential of SCS as an alternative approach for synthesis of DRM catalysts.