Effect of Preparation Technique on the Performance of Ni and Ce Incorporated Modified Alumina Catalysts in CO 2 Reformin
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Effect of Preparation Technique on the Performance of Ni and Ce Incorporated Modified Alumina Catalysts in CO2 Reforming of Methane Huseyin Arbag1 · H. Mehmet Tasdemir1 · Yavuz Yagizatli1 · Melike Kucuker1 · Sena Yasyerli1 Received: 31 December 2019 / Accepted: 19 April 2020 © Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract Performances of modified sol–gel alumina (MSGA) based catalysts, synthesized in an inert atmosphere and activated by Ni and Ce were investigated in C O2 reforming of methane. Two different incorporation methods were used to dope Ce into the structure of the catalysts: (i) simultaneous impregnation of Ce together with Ni (Ni–Ce@MSGA), (ii) one-pot synthesis of Ce incorporated alumina support material (Ni@Ce-MSGA). In the second case Ni was impregnated on the Ce-MSGA support. Synthesized catalysts were characterized using TPR, XRD, N2 adsorption/desorption, pyridine adsorbed DRIFT, CO2-TPD techniques. These analyses showed that the synthesized catalysts possessed reduced Ni particles, as well as mesoporous structure, Lewis acid sites and moderate basicity. The modified sol–gel alumina and modified sol–gel Ce-MSGA supported catalysts showed stable activity in C O2 reforming of methane. Ce incorporation improved catalytic activity of the synthesized catalysts and reduced the occurrence of reverse water gas shift reaction. Ni–Ce@MSGA catalyst decreased the C O2/CH4 conversion ratio much higher than Ni@Ce-MSGA catalyst. Coke analysis were determined using TGA/DTA, XRD, and SEM analysis. Especially, simultaneous impregnation of Ce and Ni catalyst inhibited coke deposition significantly due to lattice oxygen of ceria. However, coke deposition over Ni@Ce-MSGA catalyst was higher than Ni@MSGA catalyst since Ni@Ce-MSGA catalyst has higher nickel crystal size than that of Ni@MSGA catalyst. Graphic Abstract H2-CO H2-CO CH4-CO2
10.0 nm
Ni j
CH4-CO2
Ni
Ni
9.3 nm
H2-CO CH4-CO2
Ni
Ce
MSGA
MSGA MSGA
Ni@MSGA
Ni-Ce@MSGA
13.7 nm
Ni
Ni
Ce
MSGA
Ni
Deposited carbon
Ce
Ni@Ce-MSGA
Keywords Sol–gel · Mesoporous alumina · Dry reforming of methane · Nickel–cerium catalysts
1 Introductıon * H. Mehmet Tasdemir [email protected] Extended author information available on the last page of the article
Energy usage in the world has increased with the rapid increase in the world population. In parallel, the increase in the use of fossil fuels, where energy is provided to a great extent, has brought serious air pollution problems.
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C O 2 is the most important air pollutant gas and C O 2 amount in the greenhouse gases is about 80%. The other important greenhouse gas is methane with about 15% [1]. These gases cause global warming and must be removed from the environment. C O 2 reforming of methane is a remarkable reaction (R.1) due to the production of syngas (CO and H 2) while eliminating both C O2 and methane [2–6]. This syngas can be used to produce most of the hydrocarbons such as methanol, diesel fuels and dimet
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