Support effects on the structure and performance of ruthenium catalysts for the Fischer–Tropsch synthesis

Abstract

The influence of support and metal precursor on Ru-based catalysts has been studied in the\ud Fischer–Tropsch synthesis (FTS) combining flow reactor and quasi in situ infrared spectroscopy\ud experiments. A series of supported ruthenium catalysts (3 wt.%) have been prepared using two\ud different TiO2 (P25, 20% rutile and 80% anatase; Hombifine, 100% anatase) and SiO2Al2O3\ud (28% Al2O3) as supports and RuCl3nH2O as metal precursor. The catalysts were labeled as\ud RuTi0.8, RuTi1 and RuSA respectively. Another catalyst (RuTi0.8N) has been synthesized with\ud TiO2P25 and Ru(NO)(NO3)3. After thermal treatments in air at 723 K and hydrogen at 443 K,\ud ruthenium metal particles are agglomerated when pure anatase TiO2 and SiO2Al2O3 are used as\ud supports, leading to low active catalysts. In contrast, and despite the lower specific surface area of\ud TiO2P25 as compared to that of the other supports, well dispersed Ru particles are stabilized\ud on titania P25. Remarkably, electronic microscopy studies demonstrate that Ru is deposited\ud exclusively on the rutile phase of TiO2P25. The catalytic performance shown by all these\ud catalysts in FTS reactions follows the order: RuTi0.8 4 RuTi0.8N 4 RuSA c RuTi1. The same\ud trend is observed during quasi in situ FTS experiments conducted in an infrared (IR) spectroscopy\ud cell. The FTIR spectra of TiO2P25 supported samples show that both samples behave similarly\ud under the FTS reaction. This work shows that the structure of the support, rather than its specific\ud surface area or the Ru precursor, is the parameter that determines the dispersion of Ru particles,\ud hence their catalytic performance

Synthesis of TiO2–ZrO2 Mixed Oxides via the Alginate Route: Application in the Ru Catalytic Hydrogenation of Levulinic Acid to Gamma-Valerolactone

“…Generally, titania is known to be a more reducible support than zirconia [4]. According to previous works, the existence of a weak interaction of RuO x with TiO 2 was correlated to the presence of a titania anatase phase of support, as this was notably evidenced by TPR studies where low temperature effects were principal [31].…”

The oxidizing pretreatment-mediated autoreduction behaviour of cobalt nanoparticles supported on ordered mesoporous carbon for Fischer–Tropsch synthesis

“…The Fischer-Tropsch synthesis (FTS) enables a switch from coal, natural gas and biomass to ultra-clean transportation fuels and valuable chemicals, in which syngas is catalytically converted into hydrocarbons by means of the hydrogenation of adsorbed CO on transition metals. [1][2][3][4][5] The corresponding catalytic activity is considered to depend on the number of available surface metal sites. 3,6,7 In order to achieve high surface active sites, some refined approaches have been explored to prepare metal nanoparticles with high surface/interior atom ratio on the high-surface-area oxide supports, such as SiO 2 , Al 2 O 3 , TiO 2 and ZnO being the most frequently used.…”

Ruthenium-Loaded Halloysite Nanotubes as Mesocatalysts for Fischer–Tropsch Synthesis

“…In recent years, nanostructured systems including those based on metal ruthenium were actively studied for their higher reaction rate and selectivity for the main products [6][7][8][9][10]. Commonly used supports for FT catalysts are silica, alumina, zirconia, and titanium oxide [5,11,12]. Alumina-supported catalysts could give higher ruthenium dispersion compared to a silica carrier, while SiO 2 -based catalysts are characterized by low acidity resulting in higher long-chain hydrocarbon selectivity [13].…”

“…Alumina-supported catalysts could give higher ruthenium dispersion compared to a silica carrier, while SiO 2 -based catalysts are characterized by low acidity resulting in higher long-chain hydrocarbon selectivity [13]. For carbon nanotubes as a carrier in the Fischer-Tropsch synthesis, it was shown that placing metal particles inside the nanotubes leads to an increase in the efficiency of the catalysis [12][13][14][15].…”