Influence of the sol-gel preparation method on the photocatalytic NO oxidation performance of TiO2/Al2O3 binary oxides

Polat, Meryem
Soylu, Asli M.
Altunöz Erdoğan, Deniz
Erguven, Huseyin
Vovk, Evgeny I.
Ozensoy, Emrah
In the current work, TiO2/Al2O3 binary oxide photocatalysts were synthesized via two different sol-gel protocols (P1 and P2), where various TiO2 to Al2O3 mole ratios (0.5 and 1.0) and calcination temperatures (150-1000 degrees C) were utilized in the synthesis. Structural characterization of the synthesized binary oxide photocatalysts was also performed via BET surface area analysis, X-ray diffraction (XRD) and Raman spectroscopy. The photocatalytic NO(g) oxidation performances of these binary oxides were measured under UVA irradiation in a comparative fashion to that of a Degussa P25 industrial benchmark. TiO2/Al2O3 binary oxide photocatalysts demonstrate a novel approach which is essentially a fusion of NSR (NOx storage reduction) and PCO (photocatalytic oxidation) technologies. In this approach, rather than attempting to perform complete NOx reduction, NO(g) is oxidized on a photocatalyst surface and stored in the solidstate. Current results suggest that alumina domains can be utilized as active NOx capturing sites that can significantly eliminate the release of toxic NO2(g) into the atmosphere. Using either (P1) or (P2) protocols, structurally different binary oxide systems can be synthesized enabling much superior photocatalytic total NOx removal (i.e. up to 176% higher) than Degussa P25. Furthermore, such binary oxides can also simultaneously decrease the toxic NO2(g) emission to the atmosphere by 75% with respect to that of Degussa P25. There is a complex interplay between calcination temperature, crystal structure, composition and specific surface area, which dictate the ultimate photocatalytic activity in a coordinative manner. Two structurally different photocatalysts prepared via different preparation protocols reveal comparably high photocatalytic activities implying that the active sites responsible for the photocatalytic NO(g) oxidation and storage have a non-trivial nature.


KUCUKYAVUZ, Z; ALYURUK, K; AHMAD, AM (Elsevier BV, 1991-01-01)
Dipole moments of poly(propylene oxide) (PPO) samples with different tacticities were determined from dielectric constant and refractive index increment measurements, which were performed on dilute toluene and isooctane solutions. In contrast to previous reports, both refractive index increments and the dipole moment ratios showed a marked dependence on the tacticities of the samples. The dipole moment ratios of isotactic samples were greater than unity and decreased with increasing sequence concentration...
Influence of hydrogen bonding on electrochromic properties of conducting polymers
Akpinar, Hava; Nurioglu, Ayda Goycek; Toppare, Levent Kamil (2012-09-01)
4,7-Bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-2-phenyl-1H-benzo[d]imidazole (BImBEd) was synthesized via Stille coupling reaction of 4,7-dibromo-2-phenyl-1H-benzo[d]imidazole (BImB) with monostannylated 3,4-ethylenedioxythiophene (EDOT). In order to figure out the presence of an intramolecular hydrogen bonding between the amine bond of the imidazole ring and the oxygen of the EDOT molecule, different amounts of trifluoroacetic acid (TFA) and concentrated sodium hydroxide (NaOH) solutions were added duri...
Influence of FEP nanoparticles in catalyst layer on water management and performance of PEM fuel cell with high Pt loading
Avcioglu, Gokce S.; FIÇICILAR, BERKER; Eroğlu, İnci (2017-01-05)
In this study, fluorinated ethylene propylene (FEP) nanoparticles were added to catalyst layer (CL) to facilitate excess water removal from the triple phase boundary in high Pt loading (1.2 mg/cm(2)) proton exchange membrane fuel cell (PEMFC) electrodes. The loading of PEP in the catalyst ink was varied from zero to 30 weight percentage. High-performance electrodes for anode and cathode were prepared by ultrasonic spray coating technique with a commercial catalyst containing 70 wt. % Pt on carbon. Different...
Electrochemical polymerization and characterization of polyether-substituted aniline derivatives
Tirkeş, Süha; Oenal, Ahmet M. (Wiley, 2007-08-01)
New compounds consisting of aniline units linked by polyether bridges have been synthesized and their electrochemical polymerization was performed via constant potential electrolysis and cyclic voltammetry in an aqueous solution containing 3.0 moI L-1 H2SO4. Chemical polymerization was carried out using (NH4)(2)S2O8 as oxidizing agent. It was found that both methods gave the same polymer product without any cleavage of the polyether bridge between aniline rings. The polymers were characterized using the Fou...
Effect of Midsynthesis Addition of Silica to the Synthesis Medium on the Properties of MFI-Type Zeolite Membranes
Soydas, Belma; Kalıpçılar, Halil; Culfaz, Ali (American Chemical Society (ACS), 2010-06-02)
Thin zeolite membranes of MFI type were prepared on alpha-Al2O3 supports by midsynthesis addition of silica in a recirculating flow system at 95 degrees C The synthesis was started with the batch composition of 80SiO(2): 30TPAOH:1500H(2)O which was changed to 80SiO(2)center dot 9TPAOH:1500H(2)O by addition of silica Mkt 24, 48, or 72 h Compared to synthesis at constant composition. it is possible to affect the rates of nucleation and crystal growth to obtain membranes with better quality by changing the ove...
Citation Formats
M. Polat, A. M. Soylu, D. Altunöz Erdoğan, H. Erguven, E. I. Vovk, and E. Ozensoy, “Influence of the sol-gel preparation method on the photocatalytic NO oxidation performance of TiO2/Al2O3 binary oxides,” CATALYSIS TODAY, pp. 25–32, 2015, Accessed: 00, 2020. [Online]. Available: