High Zr-loaded SBA-15 cobalt catalyst for efficient NOx reduction in lean-burn exhaust

Sabbaghi, Aghil; Lam, Frank Leung Yuk; Hu, Xijun

doi:10.1016/j.apcata.2015.10.004

Cited by 16 publications

(4 citation statements)

References 89 publications

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“…The deconvolution of the O 1 s peak also confirmed the above-mentioned conclusions in Figure 1G,H. Three peaks at 533.1, 532.5, and 531.9 eV assigned to the Si-O-Si, Si-O-Zr [55] and Zr-OH [46] respectively, were observed in the Zr-SBA-15 and Zr/SBA-15 catalysts, while an additional peak at a binding energy of 530.9 eV corresponding to Zr-O-Zr bonds [46,52] existed in the Zr/SBA-15 catalyst (Figure 1H) rather than that in the Zr-SBA-15 catalyst. Furthermore, this result was consistent with the observations of Thunyaratchatanon et al [40], who concluded that no Zr-O-Zr bonds were detected with molar ratios of Zr/Si = 0.01-0.07, which possibly arose from the well-dispersed ZrO 2 on the surface of samples.…”

Section: Structural and Textural Properties Of Samplessupporting

confidence: 84%

Synthesis of Dimethyl Carbonate from CO2 and Methanol over Zr-Based Catalysts with Different Chemical Environments

et al. 2021

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The adsorption and activation of both CO2 and methanol are mainly affected by the distance of the Lewis acid site, Zr4+, and Lewis base, Zr4+/O2−, of the Zr-based catalysts. In this paper, Zr-incorporated SBA-15 (Zr-SBA-15) and Zr-grafted SBA-15 (Zr/SBA-15) catalysts were prepared with different Zr environments, and were analyzed with N2 adsorption–desorption isotherms, X-ray diffraction, UV-vis spectra, and XPS. It was proposed that Zr-SBA-15 catalyst with Si-O-Zr-OH and Zr-O-Si-OH structure exhibited non-adjacent sites between Zr4+ and Zr4+/O2−, while Zr/SBA-15 catalyst with Zr-O-Zr-OH structure showed neighboring sites between Zr4+ and Zr4+/O2−. Furthermore, the Zr/SBA-15 catalyst exhibited good catalytic activity, while no DMC was detected over the Zr-SBA-15 catalyst at the same reaction conditions. For combined in situ infrared and catalytic performance, it was indicated that the methanol and CO2 could be activated to form DMC, only when the Zr4+ and Zr4+/O2− sites existed and were adjacent to each other in the Zr-O-Zr-OH of Zr/SBA-15 catalyst.

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Section: Structural and Textural Properties Of Samplessupporting

confidence: 84%

Synthesis of Dimethyl Carbonate from CO2 and Methanol over Zr-Based Catalysts with Different Chemical Environments

et al. 2021

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“…of 533, 532.3 eV corresponded to Si‐O‐Si, Si‐O‐Zr bridging oxygen atoms in the silica framework while, the peak at B.E. of 530.8 eV was assigned to non‐bridging oxygen atoms as O‐Zr . XPS data confirmed that direct synthesis method resulted in successful incorporation of Zr into the silica framework.…”

Section: Resultsmentioning

confidence: 64%

Selective Production of Furanic Ethers from Lignocellulosic Biomass over Mesoporous Zr‐Incorporated SBA‐15 Catalyst

Patil

Rode

2018

ChemistrySelect

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Etherification of furanic compounds such as furfuryl alcohol (FA) and 5-(Hydroxymethyl) furfural (5-HMF) to the corresponding ethers was successfully achieved over Zr-SBA-15 catalyst. For this purpose, various Zr-SBA-15 catalysts with different Zr/Si molar ratios in self-generated acidic environment were prepared by one-pot strategy in self-generated acidic environment. XRD analysis revealed the increase in the d-spacing from 9.021 nm for parent SBA-15 to 11.66 nm for Zr-SBA-15, confirming the incorporation of Zr into the framework without disturbing the mesoporous structure of SBA-15. For the lowest Zr concentration of 0.09 M, hexagonally ordered porous structure was found to be retained as confirmed by TEM while, increase in Zr/Si molar ratio to 0.14, resulted in loss of long range order mesoporosity. The presence of both Lewis and Brønsted acid sites in Zr-SBA-15 catalyst as evidenced by py-IR, were due to the introduction of Zr in the frame work of SBA-15. The co-existence of Lewis and Brønsted acid sites in Zr-SBA-15 was responsible to catalyze etherification of FA and esterification of levulinic acid producing 2-(Ethoxymethyl) furan and ethyl levulinate selectively, both of which are bio-derived fuel additives.

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“…Hence the engine must operate with a stoichiometric fuel to air ratio whereas an oxygen rich environment (lean burn) would yield a higher energy efficiency and less CO 2 emission. [218][219][220] A NO x direct decomposition catalyst that can operate in a higher oxygen pressure environment has been a long standing goal in the automotive industry. 210,221,222 We show that the switchable out-of-plane polarization of PbTiO 3 can effectively control the binding energies of different atoms and molecules that are present in the NO x direct decomposition process, paving the road for designing an effective catalyst for this reaction and in particular overcoming the problem of oxygen inhibition (poisoning).…”

Section: No X Direct Decomposition On Pbtiomentioning

confidence: 99%

Polarization-driven catalysis via ferroelectric oxide surfaces

Kakekhani

Ismail‐Beigi

2016

Phys. Chem. Chem. Phys.

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The surface chemistry and physics of oxide ferroelectric surfaces with a fixed polarization state have been studied experimentally for some time. Here, we discuss the possibility of using these materials in a different mode, namely under cyclically changing polarization conditions achievable via periodic perturbations by external fields (e.g., temperature, strain or electric field). We use Density Functional Theory (DFT) and electronic structure analysis to understand the polarization-dependent surface physics and chemistry of ferroelectric oxide PbTiO3 as an example of this class of materials. This knowledge is then applied to design catalytic cycles for industrially important reactions including NOx direct decomposition and SO2 oxidation into SO3. The possibility of catalyzing direct partial oxidation of methane to methanol is also investigated. More generally, we discuss how using ferroelectrics under cyclically changing polarization conditions can help overcome some of the fundamental challenges facing the catalysis community such as the limitations imposed by the Sabatier principle and scaling relations.

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High Zr-loaded SBA-15 cobalt catalyst for efficient NOx reduction in lean-burn exhaust

Cited by 16 publications

References 89 publications

Synthesis of Dimethyl Carbonate from CO2 and Methanol over Zr-Based Catalysts with Different Chemical Environments

Synthesis of Dimethyl Carbonate from CO2 and Methanol over Zr-Based Catalysts with Different Chemical Environments

Selective Production of Furanic Ethers from Lignocellulosic Biomass over Mesoporous Zr‐Incorporated SBA‐15 Catalyst

Polarization-driven catalysis via ferroelectric oxide surfaces

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