Chromium oxide（Cr₂OIn elemental analysis, especially in organic element analysis, such asCHNS/OThe determination plays a key role as a combustion catalyst and temperature regulator, with its core function being to ensure the combustion of organic matter and prevent carbon deposition in the combustion tube. Here are its specific mechanisms of action and importance:

---

Main function:

1. Efficient catalytic combustion:

Promote oxidation reaction: Chromium oxide is typically filled at the front end of the combustion tube at high temperatures600-800°CThe region has strong catalytic activity and can accelerate the reaction between organic matter and oxygen, ensuring sample decomposition.

Prevent carbon buildup: Organic compounds are prone to cracking and producing free carbon (carbon deposits) when there is a lack of oxygen or insufficient temperature. Carbon deposition will adsorb subsequent combustion products (such as sulfur oxides and nitrogen oxides), resulting in significantly lower elemental determination results (especially sulfur and nitrogen). Chromium oxide catalyzes the reaction between oxygen and carbon intermediates（`C + O₂ →CO₂`）Significantly reduce the risk of carbon buildup.

2. Stable combustion temperature:

High thermal stability: Cr₂OHigh temperature resistance (melting point)>2000°C）It can exist stably in the high-temperature zone at the front end of the combustion tube for a long time without deactivation or volatilization due to high temperature.

Maintain reaction temperature: Its high specific heat capacity helps to buffer the instantaneous temperature fluctuations during sample combustion, maintain uniform temperature in the combustion zone, and provide a stable environment for efficient oxidation.

3. Synergistic effect with other catalysts:

Often associated with copper oxide（CuO）Or cobalt oxide（Co₃O₄) Combined use:

Front end (high temperature zone): Cr₂OResponsible for initial combustion and carbon prevention.

Backend (medium temperature zone): CuOorCo₃O₄ Responsible for further oxidation of intermediate products (such asCO→CO₂) Conversion of sulfur/Halogen compounds (such asSO₃→SO₂) and adsorb interfering substances.

This combination covers the entire combustion process, ensuring that all elements are transformed into detectable and stable forms (such asCO₂H₂OTheN₂SO₂).

---

Why is preventing carbon buildup crucial?

The hazards of carbon deposition:

If combustion does not produce carbon black:

-Physical adsorption: Carbon black will adsorbSO₂NOGas such as ₓ leads to lower sulfur and nitrogen results.

-Chemical interference: Residual carbon may react with oxygen to formCOrather thanCO₂, causing carbon measurement errors.

-Blocked pipeline: Accumulated carbon black may block the combustion tube or detector, affecting the lifespan of the instrument.

Solution for chromium oxide:

By catalyzing the oxidation of carbon（`C→CO₂`）Fundamentally eliminate carbon deposits and ensure detection accuracy.

---

Other features:

-Color indication function:

The newly filled chromium oxide appears bright green. If it turns grayish black due to carbon pollution after long-term use, it may indicate the need for replacement or regeneration (by high-temperature burning with air to remove carbon deposits).

-Inert carrier:

Sometimes used as a carrier for other active catalysts (such as platinum) to improve dispersion and stability.

Tangshan Anfa Trading Co., Ltd. Spot Supply:

Chromium oxide, SA990610，25g， Swiss SANTIS, elemental analysis consumables

Application: Combustion reagent for CHNS, CHN, NCS, NC, C, and S analysis

Applicable instruments and item numbers:

CE,Finnigan,ThermoElectron(TE)33822900

Swiss Santis: SA990610

SA990610B

ElementarTM(EL):

PerkinElmerTM(PE):

corresponding number

Eurovector: E1010 1 E10101-IG

The company operates the full range of Swiss SANTIS elemental analysis consumables. Please feel free to inquire.