A study on the precipitating and aging processes of CuO/ZnO/Al₂O₃ catalysts synthesized in micro-impinging stream reactors

Abstract

Precipitating and aging processes of CuO/ZnO/Al2O3 catalysts were performed more uniformly in micro-impinging stream reactors than in stirred reactors.

Enhanced Direct Dimethyl Ether Synthesis from CO2-Rich Syngas with Cu/ZnO/ZrO2 Catalysts Prepared by Continuous Co-Precipitation

“…For the preparation of Cu-based catalysts, different synthesis methods have been established, such as conventional batch-wise co-precipitation [26][27][28], impregnation [29], deposition precipitation [30], or flame spray pyrolysis [18,31]. However, in case of the commonly used co-precipitation, alternative manufacturing approaches have been developed, based on the fundamental knowledge obtained for the key steps of nucleation, crystal growth and ripening, that have the potential for a better control of the material properties, thus paving the way to more efficient catalysts [32][33][34][35][36][37][38][39]. For Cu-based catalysts it is known that the mixing during precipitation strongly influences the initial formation of solids with regard to solid phase distribution and morphology [19,32,34,36,[40][41][42].…”

“…However, in case of the commonly used co-precipitation, alternative manufacturing approaches have been developed, based on the fundamental knowledge obtained for the key steps of nucleation, crystal growth and ripening, that have the potential for a better control of the material properties, thus paving the way to more efficient catalysts [32][33][34][35][36][37][38][39]. For Cu-based catalysts it is known that the mixing during precipitation strongly influences the initial formation of solids with regard to solid phase distribution and morphology [19,32,34,36,[40][41][42]. In conventional semi-batch operation mode, typically performed in stirred tank type reactors, the spatial and temporally inhomogeneous precipitation conditions such as temperature or reactant concentration can then result in inhomogeneous particle formation [43][44][45].…”

Application of micro-impinging stream reactors in the preparation of Co and Al co-doped Ni(OH)2 nanocomposites for supercapacitors and their modification with reduced graphene oxide

“…However, the MISR-prepared Ni-Co-Al(OH) n nanocomposites were less aggregated than the STR-prepared samples with a much smaller and more uniform particle size, due to the enhanced micromixing performance of MISR over the traditional STR, which is similar to the preparation of other composites with MISR and STR as reported previously. 30,31 The structure with loose distribution of the nanocomposites obtained by MISR could provide more surface area and higher pore volume than those by STR, which is essential for achieving superior electrode performance as a supercapacitor material. Fig.…”

Continuous synthesis of Cu/ZnO/Al2O3 nanoparticles in a co-precipitation reaction using a silicon based microfluidic reactor

“…However, for larger quantities and industrial applications a semi-batch or continuous process would be advantageous. [26][27][28][29] Catalytic performance of Cu/ZnO/(Al 2 O 3 ) is particularly influenced by the surface area of copper (SA Cu ) and the area of reactive interface with ZnO in a nanoparticulate and porous structure. 30 Metallic Cu clusters/particles are considered to be the most active sites for methanol synthesis, strongly improved by ZnO, 2,25 and Al 2 O 3 as a structural promoter 25,29 reducing NP sintering.…”

“…[26][27][28][29] Catalytic performance of Cu/ZnO/(Al 2 O 3 ) is particularly influenced by the surface area of copper (SA Cu ) and the area of reactive interface with ZnO in a nanoparticulate and porous structure. 30 Metallic Cu clusters/particles are considered to be the most active sites for methanol synthesis, strongly improved by ZnO, 2,25 and Al 2 O 3 as a structural promoter 25,29 reducing NP sintering. Fast and homogeneous mixing of the soluble metal precursors and the precipitating agent are essential for the most uniform precipitate.…”