Catalytic Performance of La-Ni/Al2O3 Catalyst for CO2 Reforming of Ethanol

Bio-derived ethanol has been considered as an attractive and alternative feedstock for dry or steam reforming reactions to generate renewable hydrogen, which may be used for replacement of conventional fossil fuels. Ethanol dry reforming (EDR) is an environmentally-friendly process since it transforms greenhouse gas, CO2 to value-added products and ethanol can be easily obtained from biomass which is free of catalyst poisons (i.e. sulphur-containing compounds). However, there are currently limited studies regarding syngas production from EDR [1, 2]. Ni-based catalysts are commonly used for reforming reactions due to its capability of C-C bond rupture, relatively low cost and high availability compared to precious metals [2]. Nevertheless, carbonaceous deposition may considerably deteriorate catalytic activity and stability of Ni-based catalysts. La promoter reportedly hindered carbon deposition and improved catalytic activity [3]. Hence, the objective of this research was to investigate the effect of La promotion on 10%Ni/Al2O3 catalyst for EDR

Optimization of Pb(II) removal using Magnetic y-Fe2O3/KCC-1 Synthesized from Palm Oil Fuel Ash

The pollution of lead, Pb(II) in water bodies has severely threatened the environment and human health due to its toxicity. Thus, removing Pb(II) from water bodies is an imperative task. In this study, the removal of Pb(II) using magnetic y-Fe2O3/KCC-1 synthesized from Palm Oil Fuel Ash (POFA) was explored. The characterization analysis confirmed a successful preparation of y-Fe2O3/KCC-1 with BET surface area and pore volume of 401 m2g-1 and 0.90 cm3g-1, respectively. The optimization by response surface methodology (RSM) with independent variables of initial Pb(II) concentration

Promising hydrothermal technique for efficient CO2 methanation over Ni/SBA-15

The comparative study of different hydrothermal treatment techniques (Reflux (R) and Teflon (T)) and without hydrothermal technique (W) towards efficient CO2 methanation over Ni/SBA-15 was discussed. X-ray diffraction (XRD), inductive coupling plasma-atomic emission spectroscopy (ICP-AES), N2 adsorption-desorption isotherms (BET), Fourier transform infrared (FTIR) spectroscopy, UV-vis diffuse reflectance spectroscopy (UV-Vis DRS), scanning electron microscope – energy dispersion x-ray (SEM-EDX), and transmission electron microscope (TEM) analysis showed that Ni/SBA-15(R) possessed fascinating catalytic properties owing to the highest surface area (814 m2/g) and pore diameter (5.49 nm) of SBA-15(R), finest metal particles (17.92 nm), strongest metal-support interaction and highest concentration of basic sites. The efficacy of Ni/SBA-15 towards CO2 methanation was descending as Ni/SBA-15(R) > Ni/SBA-15(T) > Ni/SBA-15(W), implying the outstanding performance of Ni/SBA-15(R) which in parallel with the characterization results. The lowest performance of Ni/SBA-15(W) was due to the poorest properties of support; lowest surface area and pore diameter, largest Ni sizes, weakest metal-support interaction and lowest concentration of basic sites. This study successfully developed fascinating Ni/SBA-15 through the reflux hydrothermal treatment technique for CO2 methanation

CO2 Reforming of CH4 over Ni/SBA-15: Influence of Ni Loading on the Metal-support Interaction and Catalytic Activity

The influence of Ni loading on the properties of Ni/SBA-15 and CO2 reforming of CH4 were studied. XRD, BET and TGA results indicated that the increasing Ni loading (3–10 wt%) decreased the crystallinity, surface area and physically adsorbed water content of the catalysts. FTIR, TEM and H2-TPR analysis confirmed the formation of Ni–O–Si by the substitution of surface silanol groups with Ni species and the maximum substitution of surface silanol groups with Ni were achieved at 5 wt%, while further increased in Ni loading stimulate the agglomeration of Ni particles. The activity of catalysts followed the order of 5Ni/SBA-15 > 3Ni/SBA-15 ≈ 10Ni/SBA-15 > SBA-15, with the conversion of CH4 and CO2 over 5Ni/SBA-15 was about 89% and 88% respectively, and CO2/CH4 ratio of 1.02. The superior catalytic performance of 5Ni/SBA-15 towards CO2 reforming of CH4 probably was related with the formation of metal-support interaction, Ni–O–Si, which enhanced the stabilization of the active Ni species on SBA-15 support and altered the properties of catalyst towards an excellent catalytic performance. The analysis of spent catalysts found that the presence of Ni–O–Si minimizes the growth of encapsulating graphite carbon and thus enhanced the stability of catalyst. This study provides new perspectives on the Ni-based catalyst, particularly on the influence of Ni on the metal-support interaction and catalytic performance of Ni/SBA-15 towards CO2 reforming of CH4

Evaluation of La-promoted Ni/Al2O3 Catalyst for Ethanol Dry Reforming

Greenhouse emissions from combustion of fossil fuels have led to undesirable environmental issues. Hydrogen as a clean and renewable energy is therefore demanded urgently for petroleum-based energy substitution. Although the common method for H2 production is reforming of hydrocarbons which are unsustainable, ethanol has been considered as an economically attractive feedstock for replacing hydrocarbons due to its high availability, renewability and low toxicity [1]. Ethanol steam reforming has been widely researched whilst the knowledge about dry reforming of ethanol (DRE) is still limited, especially rare-earth promoted Ni-based catalyst

Synthesis of Ni/SBA-15 For CO2 Reforming of CH4: Utilization Of Palm Oil Fuel Ash As Silica Source

In this study, Ni/SBA-15 was synthesized using Palm Oil Fuel Ash (POFA) as the silica source and was applied in the CO2 reforming of CH4 (CRM). The preparation of POFA sodium silicate (POFA-Na2SiO3) was carried using sodium hydroxide (NaOH) fusion method under several parameters including NaOH/POFA mass ratio, fusion temperature and NaOHfused POFA/H2O mass ratio. The optimum condition was achieved at NaOH/POFA mass ratio of 2:1, fusion temperature of 550 oC and NaOH-fused POFA/H2O mass ratio of 1:4, with maximum silica content of 40570 ppm. POFA-Na2SiO3 was used as the silica source for the synthesis of Ni/SBA-15(POFA), and its properties and catalytic performance were compared with Ni/SBA-15(TEOS). The physicochemical properties of the catalysts were characterized using XRD, BET and FTIR, meanwhile the catalytic performance of the catalyst was carried out in a fixed bed reactor at 800°C, atmospheric pressure and CO2/CH4 feed ratio of 1/1. The characterization results revealed that the physicohemical properties of Ni/SBA-15(POFA) were comparable with Ni/SBA-15(TEOS), except for the size of Ni and the strength of metalsupport interaction. The catalytic performance results showed that Ni/SBA-15(POFA) has comparable CO2 conversion (around 82%), but lower in CH4 conversion (differences around 27%) and stability, which might be due to the larger Ni size and weak metal-support interaction in Ni/SBA-15(POFA) as compared to Ni/SBA-15(TEOS). Although Ni/SBA-15(POFA) showed lower CH4 conversion in CRM, POFA can be considered as an alternative silica source to synthesis Ni/SBA-15 owing to the fact that the deficiency observed in the present catalyst can be improved via metal loading method

Enhanced Catalytic Performance Of Ni/Sba-15 Towards Co2 Methanation Via P123-Assisted Method

This study focused on the enhancement of catalytic performance of Ni/SBA-15 towards CO2 methanation via P123(PEG-PPG-PEG triblock copolymer)-assisted impregnation method. The pysical and chemical properties of the catalysts were characterized using XRD, BET and FTIR, meanwhile the catalytic performance of catalysts towards CO2 methanation were evaluated using stainless steel fixed bed reactor. The presence of coke on the surface of catalysts was characterized using TGA analysis. XRD and BET results revealed that the dispersion of Ni particles on the surface of SBA-15 were improved with P123 (Ni/SBA-15(P123)) as compared to without P123 (Ni/SBA-15). FTIR analysis revealed that P123 enhanced the formation of metal-support interaction (Si-O-Ni) through the substitution of O‒H with O‒Ni. Ni/SBA-15(P123) exhibited higher activity, better stability and less carbon formation owing to its smaller metal particles, stronger metal-support interaction and more homogenous metal dispersion, which altered the properties of catalyst towards an excellent catalytic performance. This study provides new perspective on the beneficial effect of P123- assisted impregnation method in the enhancement of catalytic performance of Ni/SBA-15 towards CO2 methanation

CO2 Reforming of CH4 Over Ni/SBA-15 Prepared by Surfactant-Assisted Impregnation Method: Comparative Study of Surfactant Types

This research focused on the influence of surfactant types of surfactant-assisted impregnation method on the properties and catalytic activity of Ni/SBA-15 towards CO2 reforming of CH4(CRM). Three types of surfactant were used which are nonionic surfactant (poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol), P123), cationic surfactant (cethyltrimethylammonium bromide, CTAB) and anionic surfactant (sodium dodecyl sulfate, SDS) to synthesize Ni/SBA-15(P123), Ni/SBA-15(CTAB) and Ni/SBA-15(SDS), respectively. The synthesized catalysts were characterized using X-ray Diffractometer (XRD), Brunauer-Emmett-Teller (BET) and Fourier-Transform Infrared (FTIR) to study the physical and chemical properties of synthesized catalysts. The CRM was carried out in a stainless steel fixed bed reactor at 800°C and CO2/CH4 ratio = 1/1. The obtained results indicated that the types of surfactant greatly influence the properties and catalytic activity of Ni/SBA-15. The activity of catalysts followed the order of SBA-15 < Ni/SBA-15(SDS) < Ni/SBA-15(CTAB) < Ni/SBA-15 < Ni/SBA-15(P123) with the conversion of CH4 and CO2 over Ni/SBA- 15(P123) were about 92% and 82%, respectively and H2/CO ratio of 1.22. The superior catalytic performance of Ni/SBA-15(P123) might be related with the well dispersion of Ni particles which enhanced the stabilization of the active metal sites on SBA-15 and ameliorated the properties of catalyst towards an excellent catalytic performance. This study provides a new perspective on the preparation of Ni/SBA-15, particularly in the influence of surfactant types of surfactant-assisted impregnation method towards an excellent CRM

Syngas production via CO2 reforming of CH4 over Zr-Ni/SBA-15

In the present study, the effect of Zirconium (Zr) loading (1-7wt %) as promoter on the properties of Ni/SBA-15 catalyst for production of syngas by CO2 reforming of CH4 were studied. Zirconium promoted Ni/SBA-15 catalyst was prepared using one pot sol-gel method as described in the literature [1]. The physiochemical properties of Zr-Ni/SBA-15 catalysts were characterized using XRD, BET and FTIR meanwhile the catalytic performances of the of the catalyst was carried out in a stainless steel fixed bed reactor at 800°C, atmospheric pressure and CO2/CH4 feed ratio of 1/1. The ordered mesoporous structure of SBA-15 was proven by N2 adsorption desorption isotherms. The surface area and pore volume of catalyst were decreased with the increase of Zr loading as ZrO2 particles were occupied in SBA-15 frameworks and thus destroyed SBA-15 structured [2]. ZrO2 peak of 1Zr-Ni/SBA-15 was not detected in XRD result (Fig. 1) indicates to well dispersion of the Zr species on the SBA-15 surfaces [3]. The catalytic activity test revealed that the optimum Zr loading was at 1 wt% with CH4 conversion, CO2 conversion and H2/CO ratio were 87.07%, 74.01%, and 0.42, respectively as illustrated in Fig. 2. This was due to the well dispersion of Zr that promote the Nickel (Ni) species to confine in the SBA-15 pores as proven by XRD and FTIR analysis. All catalysts showed a good stability up 900oC with less than 5 % weight loss as analyzed by TGA. The addition of 1wt % of Zr enhance the Ni dispersion which create a proper active site for CH4 and CO2 accessibility and also reduce carbon formation

Dry reforming of methane over Ni/dendritic fibrous SBA-15 (Ni/DFSBA-15) : optimization, mechanism, and regeneration studies

Dendritic fibrous type SBA-15 (DFSBA-15) was recently discovered with its outstanding catalytic performance and coke resistance as compared to the conventional SBA-15. The operating conditions for dry reforming of methane (DRM) over 10Ni/DFSAB-15 were optimized by using response surface methodology (RSM), followed by stability and regeneration study. Characterization results (TEM and FESEM) confirmed the homogenous distribution of NiO particles with no morphological change in spherical DFSBA-15 upon Ni addition. Process parameters, such as reaction temperature (X1, 700 °C–900 °C), gas hourly space velocity (X2, 15,000 mL/g.h ‒ 35,000 mL/g.h), and CH4/CO2 ratio (X3, 1–3) were studied over CO2 conversion (Y1), CH4 conversion (Y2), and H2/CO ratio (Y3). The optimal reaction conditions were found at X1 = 794.37 °C, X2 = 23,815.022 mL/g.h, and X3 = 1.199, with Y1 = 95.67%, Y2 = 93.48%, and Y3 = 0.983. The in-situ FTIR studies of adsorbed CH4, CO2, and CH4 + CO2 confirmed the formation of unidentate carbonate, bidentate carbonate, and linear carbonyl species as intermediate species. 10Ni/DFSBA-15 presented good reproducibility by using both regeneration medium (air and CO2/N2) with two-fold regeneration by air as compared to CO2/N2. It was proven that the synthesized 10Ni/DFSBA-15 was appreciably stable and prone to be regenerated by air for DRM under optimal conditions