1. What is Turn Over Number?

Definition: Turn Over Number is the number of passes or turns through the catalytic cycle before the catalyst gets deactivated.

Purpose: It helps quantify the efficiency and longevity of a catalyst in chemical reactions.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( TON \) — Turn Over Number (dimensionless)
• \( TOF \) — Turn Over Frequency (1/s)
• \( t \) — Time Taken for Reaction (s)

Explanation: The turn over frequency (rate of catalytic cycles) multiplied by the reaction time gives the total number of cycles before deactivation.

3. Importance of Turn Over Number

Details: Higher TON values indicate more efficient catalysts that can perform more reactions before becoming inactive.

4. Using the Calculator

Tips: Enter the turn over frequency in 1/s and reaction time in seconds. All values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a good Turn Over Number?
A: It varies by catalyst and reaction, but generally higher is better. Industrial catalysts often have TON > 10,000.

Q2: How is this different from Turn Over Frequency?
A: TOF measures rate (cycles per second), while TON measures total cycles over the catalyst's lifetime.

Q3: What affects Turn Over Number?
A: Catalyst stability, reaction conditions, temperature, and presence of catalyst poisons.

Q4: Can TON be less than 1?
A: No, since it represents complete catalytic cycles. Values <1 suggest the catalyst deactivates before completing one cycle.

Q5: How do I measure Turn Over Frequency?
A: Typically measured experimentally using reaction rate analysis under controlled conditions.