Time evolution of the CO2 hydrogenation to fuels over Cu-Zr-SBA-15 catalysts

Abstract

The self-archived postprint version of this journal article is available at Linköping University Institutional Repository (DiVA): http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-147297 N.B.: When citing this work, cite the original publication.Atakan, A., Erdtman, E., Mäkie, P., Ojamäe, L., Odén, M., (2018) ABSTRACT: Time evolution of catalytic CO2 hydrogenation to methanol and dimethyl ether (DME) has been investigated in a hightemperature high-pressure reaction chamber where products accumulate over time. The employed catalysts are based on a nano-assembly composed of Cu nanoparticles infiltrated into a Zr doped SiOx mesoporous framework (SBA-15): Cu-Zr-SBA-15. The CO2 conversion was recorded as a function of time by gas chromatography-mass spectrometry (GC-MS) and the molecular activity on the catalyst's surface was examined by diffuse reflectance in-situ Fourier transform infrared spectroscopy (DRIFTS). The experimental results showed that after 14 days a CO2 conversion of 25% to methanol and DME was reached when a DME selective catalyst was used which was also illustrated by thermodynamic equilibrium calculations. With higher Zr content in the catalyst, greater selectivity for methanol and a total 9.5 % conversion to methanol and DME was observed, yielding also CO as an additional product. The time evolution profiles indicated that DME is formed directly from methoxy groups in this reaction system. Both DME and methanol selective systems show the thermodynamically highest possible conversion.

Capsule‐Structured Copper–Zinc Catalyst for Highly Efficient Hydrogenation of Carbon Dioxide to Methanol

“…Additionally, the bands at 1305, 1337, 1504, and 1543 cm −1 over CZA‐r are assigned to asymmetric and symmetric stretches of (OCO) of carboxylate species (*HOCO) . Furthermore, the bands at 2170 and 2120 cm −1 assigned to adsorbed CO species on Cu faces appear at 190 °C, and another band at 3010 cm −1 attributed to the ν (CH 4 ) appears at 230 °C . The band of methane at 3014 cm −1 appears at 260 °C over CZA‐r with a weaker peak intensity than that on CZA‐p (230 °C), suggesting suppressed CH 4 formation.…”

“…Figure and Figure S9 (in the Supporting Information) show the transient evolution of the surface species under reactive atmosphere from 150 to 300 °C over CZA‐p and CZA‐r, respectively. From Figure a and Figure S5 a (in the Supporting Information), the bands at 1054 and 2928 cm −1 assigned to the ν (C‐O) and ν (CH 3 ) modes of methoxy (*H 3 CO) appear at 170 °C over CZA‐p, whereas the bands appear at 160 °C on CZA‐r (Figure b and Figure S5 b in the Supporting Information). This indicates lower activation energy over CZA‐r for CO 2 hydrogenation.…”

“…This indicates lower activation energy over CZA‐r for CO 2 hydrogenation. Over CZA‐p, the band at 2855 cm −1 corresponding to the ν (CH) of methoxy or surface adsorbed methanol appears at 170 °C . Moreover, the bands at 1308, 1337, 1514, and 1552 cm −1 over CZA‐p are assigned to asymmetric and symmetric stretches of (OCO) of carboxylate species (*HOCO) .…”

Ethanol as a Binder to Fabricate a Highly‐Efficient Capsule‐Structured CuO−ZnO−Al2O3@HZSM‐5 Catalyst for Direct Production of Dimethyl Ether from Syngas

“…Apart from the aforementioned hybrid catalysts, the supported bifunctional catalysts were also frequently used in the STD reactions . The supported catalyst can be produced by the coprecipitation, impregnation, sol‐gel, and wet‐chemical ways .…”

Homogeneous Zr and Ti co-doped SBA-15 with high specific surface area: preparation, characterization and application

“…Recently, porous nanostructured materials as adsorbent of organic dyes have been one of the most extensively studied materials owing to its large surface and abundant active sites [9], of which SBA-15 materials as a typical representative representing suitable support exhibit wellaligned nanochannels, high surface area, large pore diameter and excellent thermal stability [10], with its modification by metal atoms, including Zr [11], Ti [12], Al [13], Fe [14], widely reported in the adsorption and catalytic fields, and particularly investigations to Ti-SBA-15 used for effective removal of organic dyes from a system attracting more attentions of reaesrchers [15]. Zhang and his group [16] prepared a series of Ti-containing SBA-15 samples in the self-generated acidic condition with catalytic tests indicating that Ti-SBA-15 showed much higher photodegradation ability towards RhB than pure TiO 2 and the work from Swapan K. Das et al [17] showed that synthesized Ti-SBA-15 with higher surface area than that of pure SBA-15, possessed larger H 2 uptake at higher external pressure and excellent efficiency in photocatalytic degradation of methylene blue, which indicate that the introduction of heteroatoms in SBA-15 materials is a promising approach to enhance the SBA-15 properties.…”