Hydrogen Production from Steam Reforming of Acetic Acid over Ni-Fe/Palygorskite Modified with Cerium

Abstract

The steam reforming of acetic acid (SRA) was carried out in a fixed-bed tubular reactor with Ni-Fe/ceria-palygorskite (CPG) catalysts. The asprepared catalysts were analyzed by N2 adsorption-desorption, scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS), H2 temperature programmed reduction (H2-TPR), and X-ray diffraction (XRD). The results of H2-TPR and XRD showed that the addition of CeO2 increased the hydrogen consumption of catalysts and the interaction force between active component (Ni-Fe alloy) and carrier. Moreover, the Ni-Fe alloys were successfully synthesized in the Ni-Fe/CPG catalysts and their crystallite sizes were decreased by adding CeO2. In addition, these catalysts were employed to SRA at 600 °C, GHSV = 14427 h -1 and different molar ratio of S/C. The experimental results revealed that the Ni-Fe/C0.4PG0.6 catalyst can achieve the highest yield of H2 (87%) and HOAc conversion (95%), as well as the highest stability during the process of steam SRA. Additionally, the spent catalysts were characterized by XRD, SEM, and thermogravimetric analysis (TGA). The results showed that the addition of CeO2 enhanced the stability and activity of Ni-Fe/palygorskite catalyst and reduced the coke deposition rate on the catalyst surface.

Catalytic Steam Reforming of Biomass-Derived Oxygenates for H2 Production: A Review on Ni-Based Catalysts

“…It was also reported that, for several Ni-based catalysts, La 2 O 3 led to a decrease in coke formation [194,206,207,217,233,234] and KOH and MgO improved the stability [194,206,207,[234][235][236]. It was also observed in several studies using Ni-based catalysts that the addition of CeO 2 improved the catalyst stability, namely through the decrease of coke production [195,197,[215][216][217][218]. So, the addition of basic oxides to the Al 2 O 3 support, in a general way, enhanced the catalytic performance.…”

“…In the work of Savuto et al [197] (who studied the steam refo compounds), mayenite (Ca12Al14O33) was used as support of Ni, show tion properties that increase the resistance of the catalyst towards coke other hand, Choi et al [209] verified that a Ni/Al2O3 catalyst with a lar basic sites and few middle and strong basic sites is required to impro formance and minimize coke formation (in acetic acid steam reformin It was also reported that, for several Ni-based catalysts, La2O3 l coke formation [194,206,207,217,233,234] and KOH and MgO imp [194,206,207,[234][235][236]. It was also observed in several studies using Nithe addition of CeO2 improved the catalyst stability, namely through t production [195,197,[215][216][217][218]. So, the addition of basic oxides to the In the work of Savuto et al [197] (who studied the steam reforming of tar model compounds), mayenite (Ca 12 Al 14 O 33 ) was used as support of Ni, showing excellent oxidation properties that increase the resistance of the catalyst towards coke deposition.…”

“…Analyzing the results of oxygenates conversion, only the catalysts Ni/ABC (ABC-Activated Biochar) and 6.6 wt.% Ni-10 wt.% Fe/(CeO 2 ) 0.4 -PG 0.6 (PG, palygorskite) did not convert completely the compounds fed [203,216]. Regarding the H 2 production, it was observed that the monometallic catalysts 15 wt.% Ni/α-Al 2 O 3 and 3.5 wt.% Ni/5 wt.% La 2 O 3 -ZrO 2 demonstrated higher performance (H 2 yield of 90%) in comparison with the remaining materials [194,196].…”

“…Besides that, Bangala et al [207] observed that the presence of TiO 2 decreases the conversion since it reduces the crystallinity and robustness of the material and destroys the Al 2 O 3 matrix. It was also observed that the addition of CeO 2 improved the catalyst performance, namely through the inhibition of coke production due to the enhanced catalyst redox properties [195,197,[215][216][217][218]. So, the addition of basic oxides (e.g., MgO, CeO 2 , La 2 O 3 , etc.)…”

Olive Mill Wastewater Valorization through Steam Reforming Using Multifunctional Reactors: Challenges of the Process Intensification

“…It was reported that Cr inhibited the formation of Ni 3 C and can modify the metal sites forming alloys with Ni [132,133], La 2 O 3 led to a decrease in coke formation [105,[132][133][134][135][136], K and MgO improved the stability [105,117,132,133,[136][137][138][139], and TiO 2 decreased the conversion [132]. It was also observed that the addition of CeO 2 improved the activity and stability of the catalyst [106,108,114,135,[140][141][142].…”