Hydrogen-Rich Syngas Production by Toluene Reforming in a Microchannel Reactor Coated with Ni/MgO–Al₂O₃ Multifunctional Catalysts

Abstract

Ni/MgO−Al 2 O 3 multifunctional catalysts were synthesized and applied to toluene reforming with a microchannel reactor to obtain hydrogen-rich syngas and lowest deactivation by carbon deposition. These catalysts were characterized by inductively coupled plasma-atomic emission spectroscopy, N 2 adsorption−desorption, X-ray diffraction, H 2temperature programmed reduction, NH 3 -temperature programmed desorption, and transmission electron microscope-energydispersive spectrometer. The results showed that MgO−Al 2 O 3 support had the largest Brunauer−Emmett−Teller surface area and formed a steady MgAl 2 O 4 spinel structure after 800 °C calcination, which is conducive to preventing Ni sintering, increasing Ni dispersion, and thus improving catalytic activity. Less than 15% Ni loading maintains a high dispersion on the MgO−Al 2 O 3 support, but 20% Ni loading caused a sharp decline in the surface area and dispersion effect, which is due to Ni sintering and pore plugging. Meanwhile, 15% Ni/MgO−Al 2 O 3 shows a higher catalytic activity and excellent stability than others. In addition, the microchannel structure increased the surface area-to-volume ratio and enhanced the heat-transfer coefficient, hence had a prominently promotive effect on the catalysts utilization efficiency.

Catalytic steam reforming of toluene as model tar compound using Ni/coal fly ash catalyst

“…But after Ni loading, the BET surface area of Ni/CFA catalyst increased sharply to 15.46 m 2 /g (Table 3), and its pore volume and average pore diameter were 0.056 cm 3 /g and 9.66 nm, which were similar with other Ni‐based catalyst supporting CFA with different acid pretreatment time (6 h ~ 4 days). This can suggest that the added pores in these catalysts are mainly ascribed to the rearrangement of the Ni particles 30 . The surface area of Co‐Ni/CFA‐6h catalyst was 12.32 m 2 /g lower than that of all Ni/CFA‐ t catalysts, but its average pore diameter was larger than them.…”

“…This can suggest that the added pores in these catalysts are mainly ascribed to the rearrangement of the Ni particles. 30 The surface area of Co-Ni/CFA-6h catalyst was 12.32 m 2 /g lower than that of all Ni/CFA-t catalysts, but its average pore diameter was larger than them. It means that the sinter of metal particles is easy in exhibited the far higher surface areas, and their BET surface area were over 100 m 2 /g because the SiO 2 and Al 2 O 3 supports were expensive commercial nanomaterials contrasting with CFA.…”

Synthesis of a High-Stability Nanosized Pt-Loaded MgAl2O4 Catalyst for n-Decane Cracking with Enhanced Activity and Durability

“…For MA support, the diffraction of peaks centered at 2θ = 19.1, 31.4, 36.9, 44.9, 59.6, and 65.6° correspond to the different crystallographic planes of the MgAl 2 O 4 spinel (JCPDS card no. 73-1959) . However, the lack of detectable diffractions for the Pt or PtO x phase (2θ = 39.8, 46.2, 67.5°) results from a high dispersion of Pt species, or the average Pt sizes are below the detection limit of XRD in PMA and PMA-V samples. ,, In order to better understand the phase transformation after Pt doping by different methods, the amplifying patterns are also presented in Figure b,c.…”

“…73-1959). 53 However, the lack of detectable diffractions for the Pt or PtO x phase (2θ = 39.8, 46.2, 67.5°) results from a high dispersion of Pt species, or the average Pt sizes are below the detection limit of XRD in PMA and PMA-V samples. 46,54,55 In order to better understand the phase transformation after Pt doping by different methods, the amplifying patterns are also presented in Figure 5b,c.…”

Continuous-Flow Ammoxidation of 2-Methylpyrazine to 2-Cyanopyrazine with High Space-Time Yield in a Microreactor

“…Especially, when the flow rate of MP was high in a FBR reactor, the expansion of hot spots in the catalyst bed might increase byproducts of carbon oxides and reduce the yield of CP . With respect to the results of higher reaction temperature can raise the MP conversion and may be tolerated by the microreactor, − obviously a continuous-flow microreactor carrying out MP ammoxidation stably at higher temperature would be an ideal reactor for efficiently synthesis CP. Especially, a continuous microfluidic flow would imbue an improved safety profile through the use of reduced volumes of gas within limited explosion space, which is also called the intrinsic safety of microreactors.…”