The catalytic reduction of NO with NH₃ (NH₃-SCR) on phosphorus-doped carbon aerogels (P-CAs) was studied in the temperature range of 100–200 °C. The P-CAs were prepared by a one-pot sol–gel method by using phosphoric acid as a phosphorus source followed by carbonization at 600–900 °C. A correlation between catalytic activity and surface P content is observed. The P-CA-800_vac sample obtained via carbonization at 800 °C and vacuum treatment at 380 °C shows the highest NO conversion of 45.6–76.8% at 100–200 °C under a gas hourly space velocity of 500 h⁻¹ for the inlet gas mixture of 500 ppm NO, 500 ppm NH₃ and 5.0 vol% O₂. The coexistence of NH₃ and O₂ is essential for the high conversion of NO on the P-CA carbon catalysts, which can decrease the spillover of NO₂ and N₂O. The main Brønsted acid sites derived from P-doping and contributed by the C–OH group at edges of carbon sheets are beneficial for NH₃ adsorption. In addition, the C₃–PO configuration seems to have the most active sites for favorable adsorption and dissociation of O₂ and facilitates the formation of NO₂. Therefore, the simultaneous presence of acidic groups for NH₃ adsorption and the C₃–PO active sites for NO₂ generation due to the activation of O₂ molecules is likely responsible for the significant increase in the NH₃-SCR activity over the P–CAs. The transformation of C₃–PO to C–O–P functional groups after the reaction is found, which could be assigned to the oxidation of C₃–PO by the dissociated O*, resulting in an apparent decrease of catalytic activity for P-CAs. The C–O–P based functional groups are also active in the NH₃-SCR reaction.

Novel Mn–Ce–Ti–O composite aerogels with large mesopore size were prepared via a one-pot sol–gel method by using propylene oxide as a network gel inducer and ethyl acetoacetate as a complexing agent. The effect of calcination temperature (400, 500, 600, and 700 °C) on the NH₃–selective catalytic reduction (SCR) performance of the obtained Mn–Ce–Ti–O composite aerogels was investigated. The results show that the Mn–Ce–Ti–O catalyst calcined at 600 °C exhibits the highest NH₃–SCR activity and lowest apparent activation energy due to its most abundant Lewis acid sites and best reducibility. The NO conversion of the MCTO-600 catalyst maintains 100% at 200 °C in the presence of 100 ppm SO₂, showing the superior resistance to SO₂ poisoning as compared with the MnO_x–CeO₂–TiO₂ catalysts reported the literature. This should be mainly attributed to its large mesopore sizes with an average pore size of 32 nm and abundant Lewis acid sites. The former fact facilitates the decomposition of NH₄HSO₄, and the latter fact reduces vapor pressure of NH₃. The NH₃–SCR process on the MCTO-600 catalyst follows both the Eley–Rideal (E–R) mechanism and the Langmuir–Hinshelwood (L–H) mechanism.

Boron doped carbon aerogel could increase the number of active sites effectively and enhance NO reduction to N ₂ via NH ₃ -SCR.

In this work, graphite flake-carbon composites were fabricated from natural graphite flake and spinning pitch by a hot-pressing technique at 500°C and 10 MPa. The X-ray pole figure measurements show that the orientation degree of graphitized composite is higher than that of hot-pressed and carbonized composite and presents a descending tendency from 74.4 to 71.2% when the pitch content increases from 4 to 14 wt.%. A reducing trend of d₀₀₂ and an increasing tendency of the average crystallite diameter (L_a), crystallite stack height (L_c) and degree of graphitization (g) can also be observed when pitch fraction increases from 4 to 16 wt.%. The apparent density and thermal conductivity in the direction perpendicular to the hot-pressing direction of graphitized composite with 16 wt.% of binder all achieve maximum values, 1.930 g/cm³ and 485 W/m K, respectively.