Platinum-loaded lanthanum-doped calcium titanate photocatalysts prepared by a flux method for photocatalytic steam reforming of methane

Anzai, Akihiko; Fujiwara, Kenji; Yamamoto, Akira; Yoshida, Hisao

doi:10.1016/j.cattod.2020.02.027

Cited by 22 publications

(17 citation statements)

References 39 publications

(61 reference statements)

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“…[10] Thedoping of La 3+ can affect the methane conversion activity by changing the number of edge active sites in GaTiO 3 . [11] However,r egarding the low conversion efficiency caused by the extremely inert CÀHbond, more attention is required to explore the influence of dopant-involved atomic arrangement and electronic structure on the CÀHa ctivation. Currently, there is still alack of study about the effect of dopant type or activation sites of the C À Hb ond as well as the subsequent C À Ccoupling formed by doming.…”

Section: Introductionmentioning

confidence: 99%

Non‐oxidative Coupling of Methane: N‐type Doping of Niobium Single Atoms in TiO₂–SiO₂ Induces Electron Localization

Chen

et al. 2021

Angew Chem Int Ed

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Photodriven nonoxidative coupling of CH4 (NOCM) is an attractive potential way to use abundant methane resources. Herein, an n‐type doped photocatalyst for NOCM is created by doping single‐atom Nb into hierarchical porous TiO2–SiO2 (TS) microarray, which exhibits a high conversion rate of 3.57 μmol g−1 h−1 with good recyclability. The Nb dopant replaces the 6‐coordinated titanium on the (1 0 1) plane and forms shallow electron‐trapped surface polarons along [0 1 0] direction and the comparison of different models proves that the electron localization caused by the n‐type doping is beneficial to both methane activation and ethane desorption. The positive effect of n‐type dopant on CH4 conversion is further verified on Mo‐, W‐ and Ta‐doped composites. In contrast, the doping of p‐type dopant (Ga, Cu, Fe) shows a less active influence.

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Section: Introductionmentioning

confidence: 99%

Non‐oxidative Coupling of Methane: N‐type Doping of Niobium Single Atoms in TiO₂–SiO₂ Induces Electron Localization

Chen

et al. 2021

Angew Chem Int Ed

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“…Calcium titanate (CaTiO 3 ) would be a suitable photocatalytic material for the assessment of the possibility of this new reaction system (eq 7), since it has been reported as a photocatalyst for water splitting, 22,23 CO 2 reduction, 5,24 and so on. 25 In this study for the first time, we found that a CaTiO 3 (CTO) photocatalyst loaded with a silver−manganese oxide (Ag−MnO x ) dual cocatalyst enabled the simultaneous production of CO and H 2 O 2 from CO 2 and H 2 O without the application of any external bias and consumption of any compounds, which is referred to as a Ag−MnO x /CTO photocatalyst. An aqueous solution of HCO 3 − was found to specifically permit oxidative H 2 O 2 production and accumulation in the aqueous solution, i.e., a high H 2 O 2 concentration such as 0.6 mM was achieved after a 24 h reaction, which is a comparable production rate to the reported values in an electrochemical system using a MnO x electrocatalyst, 26 a PEC system with a WO 3 /BiVO 4 photoanode, 15 and so on (Table S1).…”

Section: Introductionmentioning

confidence: 95%

Simultaneous Formation of CO and H₂O₂ from CO₂ and H₂O with a Ag–MnO_x/CaTiO₃ Photocatalyst

Soltani

Yamamoto

Singh

et al. 2021

ACS Appl. Energy Mater.

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Carbon monoxide (CO) is an important feedstock for the chemical industry, and hydrogen peroxide (H2O2) is also an important chemical with versatile applications. Here, a photocatalytic system was discovered for the simultaneous production of CO and H2O2 from CO2 and H2O with both high activity and selectivity without any externally applied voltage and any consumption of chemical compounds, which was promoted by using a calcium titanate (CaTiO3) photocatalyst modified with a silver–manganese oxide (Ag–MnO x ) dual cocatalyst. Although a Ag/CaTiO3(CTO) photocatalyst was reported to reduce CO2 with water to form CO and O2, the coexistence of MnO x species with silver nanoparticles (NPs) not only improved the CO formation rate more than 2 times with a selectivity of 76% but also changed the selectivity of the oxidative reaction and forms H2O2 instead of O2 with a high selectivity of 99%. The Ag NPs promoted the CO2 reduction to CO by the photoexcited electrons, and the Mn(III) oxide species deposited on the CaTiO3 surface contributed to the water oxidation to H2O2 by the positive holes in the aid of HCO3 – as a reaction mediator. The produced CO is easily separated from the aqueous solution to the gas phase, and the H2O2 is stably stored in the aqueous HCO3 – solution. This photocatalytic system can utilize the stable and ubiquitous molecules (CO2 and H2O) to produce reactive and useful molecules (CO and H2O2), concurrently, meaning that it can convert photoenergy to storable chemical energy to increase sustainability.

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“…Recently, photocatalytic steam reforming has come to be considered as a promising route for hydrogen production [27][28][29]. There are several factors affecting hydrogen production in photocatalytic steam reforming, such as the intensity of the solar radiation, type and amount of the active photocatalyst, time of the irradiation, the methane to steam ratio, etc.…”

Section: Introductionmentioning

confidence: 99%

Parameter Estimation-Based Slime Mold Algorithm of Photocatalytic Methane Reforming Process for Hydrogen Production

Nassef

Handam

2022

Sustainability

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The key contribution of this paper is to determine the optimal operating parameters of the methane reforming process for hydrogen production. The proposed strategy contained two phases: ANFIS modelling and optimization. Four input controlling parameters were considered to increase the hydrogen: irradiation time (min), metal loading, methane concentration, and steam concentration. In the first phase, an ANFIS model was created with the help of the experimental data samples. The subtractive clustering (SC) technique was used to generate the fuzzy rules. In addition, the Gaussian-type and weighed average were used for the fuzzification and defuzzification methods, respectively. The reliability of the resulting model was assessed statistically by RMSE and the correlation (R2) measures. The small RMSE value and high R2 value of testing samples assured the correctness of the modelling phase, as they reached 0.0668 and 0.981, respectively. Based on the robust model, the optimization phase was applied. The slime mold algorithm (SMA), as a recent as well as simple optimizer, was applied to look for the best set of parameters that maximizes hydrogen production. The resulting values were compared by the findings of three competitive optimizers, namely particle swarm optimization (PSO), Harris hawks optimization (HHO), and evolutionary strategy HHO (EESHHO). By running the optimizers 30 times, the statistical results showed that the SMA obtained the maximum value with high mean, standard deviation, and median. Furthermore, the proposed strategy of combining the ANFIS modelling and the SMA optimizer produced an increase in the hydrogen production by 15.7% in comparison to both the experimental and traditional RSM techniques.

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Platinum-loaded lanthanum-doped calcium titanate photocatalysts prepared by a flux method for photocatalytic steam reforming of methane

Cited by 22 publications

References 39 publications

Non‐oxidative Coupling of Methane: N‐type Doping of Niobium Single Atoms in TiO₂–SiO₂ Induces Electron Localization

Non‐oxidative Coupling of Methane: N‐type Doping of Niobium Single Atoms in TiO₂–SiO₂ Induces Electron Localization

Simultaneous Formation of CO and H₂O₂ from CO₂ and H₂O with a Ag–MnO_x/CaTiO₃ Photocatalyst

Parameter Estimation-Based Slime Mold Algorithm of Photocatalytic Methane Reforming Process for Hydrogen Production

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Platinum-loaded lanthanum-doped calcium titanate photocatalysts prepared by a flux method for photocatalytic steam reforming of methane

Cited by 22 publications

References 39 publications

Non‐oxidative Coupling of Methane: N‐type Doping of Niobium Single Atoms in TiO2–SiO2 Induces Electron Localization

Non‐oxidative Coupling of Methane: N‐type Doping of Niobium Single Atoms in TiO2–SiO2 Induces Electron Localization

Simultaneous Formation of CO and H2O2 from CO2 and H2O with a Ag–MnOx/CaTiO3 Photocatalyst

Parameter Estimation-Based Slime Mold Algorithm of Photocatalytic Methane Reforming Process for Hydrogen Production

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Non‐oxidative Coupling of Methane: N‐type Doping of Niobium Single Atoms in TiO₂–SiO₂ Induces Electron Localization

Non‐oxidative Coupling of Methane: N‐type Doping of Niobium Single Atoms in TiO₂–SiO₂ Induces Electron Localization

Simultaneous Formation of CO and H₂O₂ from CO₂ and H₂O with a Ag–MnO_x/CaTiO₃ Photocatalyst