Ceramic catalysts carriers
for purification of gasoline and diesel automobile engines exhaust
A catalyst is a substance that accelerates the course of a chemical
reaction without undergoing an irreversible change. Catalysts are
important not only for the chemical industry, but also for solving
environmental problems.
Ceramic structures with a high specific surface are used as
carriers for catalysts. The high specific surface should be
preserved after long-term use, as well as geometry and mechanical
properties, which implies the carrier’s resistance to thermal and
mechanical stresses and to chemical destruction.
Physical and Chemical Properties
| Items | Unit | Index |
| Chemical Composition | SiO2 | % | 49-51 |
| Al2O3 | % | 33-35 |
| MgO | % | 13-14 |
| Wall Thickness | mm | 100 CPSI | 0.43 |
| | 200 CPSI | 0.32 |
| | 300 CPSI | 0.30 |
| | 400 CPSI | 0.18 |
| | 600 CPSI | 0.15 |
| Crush Strength | A-axis | Mpa | | ≥16 |
| B-axis | Mpa | | ≥3 |
| Water Absorption | % | | 25±2 |
| Coefficient of Thermal Expansion | 10-6/K-1 | | 0.8-2.0 |
| Maximum Operating Temperature | °C | | ≥1370 |
| Bulk Density | Kg/L | 0.43-0.75 |
Ceramic catalysts carriers are usually used:
for purification of gasoline and diesel automobile engines exhaust;
for chemical and petroleum refining processes;
for cleaning emissions of power plants and other industrial
enterprises.
The main requirements for catalyst carriers include a large surface
area, heat resistance, porosity, chemical inertness, mechanical
strength.
Ceramic and metal carriers compete with each other: ceramics are
often more stable and more economical, and therefore dominate in
most sectors. Metal is sometimes preferable because of greater
mechanical strength and the ability to manufacture catalysts of a
certain geometry using wire, foil or thin-wall honeycomb
structures.
Product Characteristics
● Large specific surface area: to ensure full access to the exhaust
gas with the catalyst.
● Stable water absorption: to ensure the catalyst evenly firmly
attached to the surface of the catalyst carrier.
● Warm-up: after start-up the engine, the temperature of the
carrier can reach the catalyst activation temperature in the
shortest possible time.
● Low exhaust resistance: the engine’s exhaust resistance is small,
to ensure that doesn’t affect the engine performance.
● High strength: the operating environment of the catalyst carrier
is in the bumpy car, so the catalyst carrier must be high strength
without being external damage.
● Good assembly: the carrier is an exhaust assembly parts, only
good appearance and precise dimensions can ensure perfect assembly.
