posted on 2023-11-20, 13:36authored byAlua Manabayeva, Päivi Mäki-Arvela, Zuzana Vajglová, Mark Martinez-Klimov, Olha Yevdokimova, Anssi Peuronen, Mika Lastusaari, Teija Tirri, Kaisar Kassymkan, Tolkyn S. Baizhumanova, Manapkhan Zhumabek, Rabiga O. Sarsenova, Zauresh T. Zheksenbaeva, Gulnar N. Kaumenova, Vincenzo Russo, Dmitry Yu. Murzin, Svetlana A. Tungatarova
Dry reforming of
methane (DRM) was investigated using Ni–M
oxide catalysts prepared by solution combustion synthesis (SCS) and
compared with Ni/α-Al2O3 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, CeAlO3 and LaAlO3 phases during
the reaction. For studied catalysts featuring low surface areas ranging
from 3 to 12 m2/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-Al2O3. DRM tests were conducted
for different TOSs, demonstrating that the highest CH4 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 H2/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-Al2O3, 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.