Highly dispersed ni nanocatalysts derived from nimnal-hydrotalcites as high-performing catalyst for low-temperature syngas

TY - JOUR

T1 - Highly dispersed ni nanocatalysts derived from nimnal-hydrotalcites as high-performing catalyst for low-temperature syngas

AU - Lu, Bin

AU - Zhuang, Jiahao

AU - Du, Jinping

AU - Gu, Fangna

AU - Xu, Guangwen

AU - Zhong, Ziyi

AU - Liu, Qing

AU - Su, Fabing

N1 - Publisher Copyright: © 2019 by the authors. Licensee MDPI, Basel, Switzerland.

PY - 2019/3

Y1 - 2019/3

N2 - Increasing the low-temperature performance of nickel-based catalysts in syngas methanation is critical but very challenging, because at low temperatures there is high concentration of CO on the catalyst surface, causing formation of nickel carbonyl with metallic Ni and further catalyst deactivation. Herein, we have prepared highly dispersed Ni nanocatalysts by in situ reduction of NiMnAl-layered double hydroxides (NiMnAl-LDHs) and applied them to syngas methanation. The synthesized Ni nanocatalysts maintained the nanosheet structure of the LDHs, in which Ni particles were decorated with MnOy species and embedded in the AlOx nanosheets. It was observed that the Ni nanocatalysts exhibited markedly better low-temperature performance than commercial catalysts in the syngas methanation. At 250 °C, 3.0 MPa and a high weight hourly space velocity (WHSV) of 30,000 mLg-1h-1, both the CO conversion and the CH4 selectivity reached 100% over the former, while those over the commercial catalyst were only 14% and 76%, respectively. Furthermore, this NiMnAl catalyst exhibited strong anti-carbon and anti-sintering properties at high temperatures. The enhanced low-temperature performance and high-temperature stability originated from the promotion effect of MnOy and the embedding effect of AlOx in the catalyst.

AB - Increasing the low-temperature performance of nickel-based catalysts in syngas methanation is critical but very challenging, because at low temperatures there is high concentration of CO on the catalyst surface, causing formation of nickel carbonyl with metallic Ni and further catalyst deactivation. Herein, we have prepared highly dispersed Ni nanocatalysts by in situ reduction of NiMnAl-layered double hydroxides (NiMnAl-LDHs) and applied them to syngas methanation. The synthesized Ni nanocatalysts maintained the nanosheet structure of the LDHs, in which Ni particles were decorated with MnOy species and embedded in the AlOx nanosheets. It was observed that the Ni nanocatalysts exhibited markedly better low-temperature performance than commercial catalysts in the syngas methanation. At 250 °C, 3.0 MPa and a high weight hourly space velocity (WHSV) of 30,000 mLg-1h-1, both the CO conversion and the CH4 selectivity reached 100% over the former, while those over the commercial catalyst were only 14% and 76%, respectively. Furthermore, this NiMnAl catalyst exhibited strong anti-carbon and anti-sintering properties at high temperatures. The enhanced low-temperature performance and high-temperature stability originated from the promotion effect of MnOy and the embedding effect of AlOx in the catalyst.

KW - Low-temperature methanation

KW - Ni nanocatalysts

KW - NiMnAl-LDHs

KW - Nickel carbonyl

UR - http://www.scopus.com/inward/record.url?scp=85064211706&partnerID=8YFLogxK

U2 - 10.3390/catal9030282

DO - 10.3390/catal9030282

M3 - 文章

AN - SCOPUS:85064211706

SN - 2073-4344

VL - 9

JO - Catalysts

JF - Catalysts

IS - 3

M1 - 282

ER -