Synthesis of Sulfur-Resistant TiO2-CeO2 Composite and Its Catalytic Performance in the Oxidation of a Soluble Organic Fraction from Diesel Exhaust

Abstract

Sulfur poisoning is one of the most important factors deteriorating the purification efficiency of diesel exhaust after-treatment system, thus improving the sulfur resistibility of catalysts is imperative. Herein, ceria oxygen storage material was introduced into a sulfur-resistant titania by a co-precipitation method, and the sulfur resistibility and catalytic activity of prepared TiO 2 -CeO 2 composite in the oxidation of diesel soluble organic fraction (SOF) were studied. Catalytic performance testing results show that the CeO 2 modification significantly improves the catalytic SOF purification efficiency of TiO 2 -CeO 2 catalyst. SO 2 uptake and energy-dispersive X-ray (EDX) results suggest that the ceria doping does not debase the excellent sulfur resistibility of bare TiO 2 , the prepared TiO 2 -CeO 2 catalyst exhibits obviously better sulfur resistibility than the CeO 2 and commercial CeO 2 -ZrO 2 -Al 2 O 3 . X-ray powder diffraction (XRD) and Raman spectra indicate that cerium ions can enter into the TiO 2 lattice and not form complete CeO 2 crystals. X-ray photoelectron spectroscopy (XPS), H 2 -temperature programmed reduction (H 2 -TPR) and oxygen storage capacity (OSC) testing results imply that the addition of CeO 2 in TiO 2 -CeO 2 catalyst can significantly enhance the surface oxygen concentration and oxygen storage capacity of TiO 2 -CeO 2 .

Preparation of CexZr1–xO2 by Different Methods and Its Catalytic Oxidation Activity for Diesel Soot

“…The results are shown in Figure 8 . The multiple reduction peaks at 340–550 °C can be seen as a result of the step-by-step reduction of lattice oxygen on the surface of the catalyst, 34 while the reduction peak at approximately 770 °C can be attributed to the reduction of lattice oxygen in the bulk phase of the catalyst. When the temperature is above 600 °C, soot can be actively burned under aerobic conditions.…”

Tailoring Cadmium Composition on Titanium Dioxide to Achieve Enhanced Photocatalytic Glucose Fuel Cell Anode Performance

“…This value range was observed by many researchers. 39,40 When the Cd metal is added, it increases its reducibility of TiO 2 ; hence, the reduction temperature decreases. As seen in Figure 6a, as the amount of Cd increases, the reducing temperature decreases, and the reducibility increases.…”

Emissions Control Catalysis

“…On the other hand, a major part of contributions (9/21) concerns original research on nitrogen oxides reduction processes [20][21][22][23][24][25][26][27][28], reflecting the fact that this topic still remains hot among the targets of environmental catalysis. Five out of 21 studies concern CO and hydrocarbons oxidation processes [29][30][31][32][33] while the remained 4/21 concern CO 2 capture/recycling processes under the view of cyclic economy [34][35][36][37].…”

“…Taking into account that sulfur poisoning is one of the most important factors deteriorating the efficiency of diesel exhaust after-treatment systems and that bare TiO 2 appears high sulfur resistivity, Zhang et al [33] prepared TiO 2 -CeO 2 composites by co-precipitation and studied their sulfur resistance and catalytic activity in the oxidation of diesel soluble organic fraction (SOF). They found that TiO 2 -modification of CeO 2 significantly improves the catalytic SOF purification efficiency of CeO 2 besides the fact that this ceria doping does not downgrade the excellent sulfur resistance of bare TiO 2 ; the prepared TiO 2 -CeO 2 exhibited superior sulfur resistance than e CeO 2 and commercial CeO 2 -ZrO 2 -Al 2 O 3 .…”