Silicon Carbide Diesel Oxidation Catalyst Excavator High-Performance DOC
Name Analysis
Silicon Carbide DOC:
Silicon Carbide (SiC): A high-performance ceramic material with extremely high thermal stability and mechanical strength, replacing traditional cordierite ceramics or metal carriers.
DOC: Diesel Oxidation Catalyst, which reduces HC, CO and some PM in exhaust gas through oxidation reaction.
Characteristics
Material Characteristics:
High temperature resistance: Silicon carbide can withstand high temperatures above 1000°C for a long time, and instantaneous temperature resistance can reach 1400°C (better than cordierite ceramics).
High thermal conductivity: The thermal conductivity is more than 5 times that of cordierite, and the heat distribution is uniform, reducing the risk of local overheating.
Chemical inertness: Resistant to acid and alkali corrosion, and resistant to common poisons in exhaust gas such as sulfur and phosphorus.
Structural characteristics:
Porous structure: The surface of the carrier is coated with a high specific surface area alumina coating, loaded with precious metal catalysts such as platinum (Pt) and palladium (Pd).
Low thermal expansion coefficient: not easy to crack at high temperature, excellent thermal shock resistance.
Function
Core function:
Oxidation of harmful components in exhaust gas:
HC (hydrocarbon) → H₂O + CO₂
CO (carbon monoxide) → CO₂
SOF (soluble organic matter) → Reduce particulate matter (PM) emissions.
Generate NO₂: Oxidize part of NO to NO₂, assist DPF passive regeneration (NO₂ reacts with soot to generate CO₂ and N₂).
Auxiliary function:
Protect downstream components (such as SCR catalyst) from unburned HC or CO pollution.
Reduce exhaust odor (oxidation of sulfur compounds, etc.).
Advantages
High temperature stability:
Suitable for high-load diesel engines (such as heavy trucks, construction machinery), to avoid carrier melting or sintering.
Long life:
Strong resistance to thermal aging, 30%~50% longer life than ceramic DOC under harsh working conditions.
Efficient catalysis:
High thermal conductivity enables the catalyst to quickly reach the operating temperature, improving the conversion efficiency during the cold start phase.
System compatibility:
Can be integrated with post-treatment systems such as DPF and SCR, especially suitable for DPF systems that require high-temperature regeneration.
Environmental protection:
Reduce the risk of precious metal leakage due to carrier failure (silicon carbide carrier is more stable).
