DOC Metal Catalyst for Diesel Engines - High Efficiency Exhaust Treatment DOC Catalytic Converter
Name Analysis
Metal DOC:
Metal: refers to the carrier material of the catalyst as metal (such as honeycomb metal substrate), which is different from the traditional ceramic carrier (such as cordierite).
DOC: Diesel Oxidation Catalyst, which reduces harmful pollutants in exhaust gas through oxidation reaction.
Characteristics
Material characteristics:
Metal substrate: usually adopts high temperature resistant alloy (such as iron chromium aluminum fiber), with high mechanical strength and impact resistance.
Coating: The surface is coated with active catalytic materials (such as platinum, palladium and other precious metals) to promote oxidation reaction.
Structural characteristics:
High porosity design: The metal carrier can be made into a thinner wall and denser honeycomb structure to reduce back pressure.
Quick ignition: Metal has good thermal conductivity and can quickly reach the temperature required for catalytic reaction.
Environmental adaptability:
High temperature resistance (up to 1000°C or more), better thermal shock resistance than ceramic carrier.
Functions
Core functions: Convert harmful components in exhaust gas through catalytic oxidation reactions:
Hydrocarbons (HC) → Oxidized to H₂O and CO₂.
Carbon monoxide (CO) → Oxidized to CO₂.
Particulate matter (PM): Some soluble organic matter (SOF) is oxidized to reduce PM emissions.
NO: A small amount of NO is oxidized to NO₂ (to provide support for subsequent SCR or DPF regeneration).
Auxiliary functions:
Provide NO₂ to DPF (diesel particulate filter) to promote passive regeneration (NO₂ oxidizes soot particles).
Reduce exhaust odor (oxidized sulfides, etc.).
Advantages
Performance advantages:
High efficiency and low temperature activity: Metal has fast thermal conductivity and ignites faster during cold start (especially in short-distance driving in cities).
Low back pressure: The flow channel design of the metal carrier is more flexible, reducing engine power loss.
Long life: Resistant to mechanical vibration and thermal shock, suitable for harsh working conditions (such as construction machinery and commercial vehicles).
Application advantages:
Compact design: The metal carrier can be made into a special-shaped structure to adapt to vehicles with limited space.
Strong compatibility: It can be integrated with post-treatment systems such as SCR and DPF.
Maintenance advantages:
Not easy to break, strong resistance to sulfur poisoning (depending on the catalyst formula).
