TPR and TPS

1. TPR and TPS • Temperature Programmed Reduction (TPR) • characterisation of oxidic catalysts and other reducible catalysts • qualitative information on oxidation state • quantitative kinetic data • optimisation of catalyst pretreatment • Temperature Programmed Sulphiding (TPS) • similar to TPR Catalysis and Catalysts - TPR and TPS

2. Examples of TPR Reduction of oxidic species: Study of coke deposits: Reduction of sulphides: MO + H2 M + H2O coke + H2 hydrocarbons + H2O MS + H2 M + H2S Catalysis and Catalysts - TPR and TPS

3. Thermodynamics G0 (kJ/mol) T (K) Catalysis and Catalysts - TPR and TPS

4. Equipment for TPR reactor H / Ar 2 molsieve FID TCD Catalysis and Catalysts - TPR and TPS

5. e d c b a 400 800 1200 400 800 1200 400 800 1200 TPR of 9.1 wt% CoO/Al2O3 j i h g f o n m l k Temperature (K) Temperature (K) Temperature (K) Catalysis and Catalysts - TPR and TPS

6. TPR Patterns of Reference Materials TCD CoAl2O4 FID Co3O4 CoO 400 800 1200 Temperature (K) Catalysis and Catalysts - TPR and TPS

7. Influence of ‘hard’ and ‘soft’ Ions CoMoO4 CoAl2O4 Co3O4 400 800 1200 Temperature (K) Catalysis and Catalysts - TPR and TPS

8. TPS of MoO3/Al2O3 Reactions: MO + H2 M + H2O MO + H2S  M + H2O + S MO + H2S  MS + H2O M + H2S  MS + H2 Catalysis and Catalysts - TPR and TPS

9. TPS of MoO3/Al2O3 e 100 mg, 4.5 atoms/nm2 200 mg, 2.2 atoms/nm2 400 mg, 1.0 atoms/nm2 800 mg, 0.5 atoms/nm2 400 mg, carrier d c b a 50% H2S conversion Catalysis and Catalysts - TPR and TPS 0 20 40 400 600 800 1000 1200 Time (min) Temperature (K)

10. TPS of MoO3/Al2O3 100 mg 4.5 atoms/nm2 H2 H2S H2O 400 600 800 1000 1200 Catalysis and Catalysts - TPR and TPS Temperature (K)

11. O O O S S S S S + H S + H S + H S 2 2 2 M o M o M o M o - H O - H O - H O 2 2 2 O O O O O O O S A l A l A l A l A l A l A l A l I I I I I V I I - S - S - S O S S + H + H S + H S 2 2 2 M o M o M o - H O - H O - H O 2 2 2 O O O O O S A l A l A l A l A l A l V I V I I V Molecular Scheme of Sulphiding Catalysis and Catalysts - TPR and TPS

12. Modelling of TPR Patterns Catalysis and Catalysts - TPR and TPS

13. Kinetic Models for Reduction Catalysis and Catalysts - TPR and TPS

14. Catalysis and Catalysts - TPR and TPS

15. TPR of Fe2O3 H2/Ar saturated with 3% H2O 7.0 mg 15.9 mg 8.2 mg 3.6 mg d dry H2/Ar c b a 500 600 700 Temperature (K) Catalysis and Catalysts - TPR and TPS

16. TPR of Fe2O3 as a Function of Heating Rate 10.0 K/min 0.08 mg f Dry H2/Ar 5.0 K/min 0.19 mg e 2.0 K/min 0.91 mg d 1.0 K/min 1.8 mg c b 0.5 K/min 2.8 mg a 0.2 K/min 3.6 mg 500 600 700 Temperature (K) Catalysis and Catalysts - TPR and TPS

17. TPR of Fe2O3 as a Function of Heating Rate f 10.0 K/min 0.17 mg Wet H2/Ar (3% H2O) e 5.0 K/min 0.33 mg d 2.0 K/min 0.90 mg 1.0 K/min 1.5 mg c 0.5 K/min 2.6 mg b 0.2 K/min 7.0 mg a 500 600 700 800 Temperature (K) Catalysis and Catalysts - TPR and TPS

18. (10-4 K-1) Arrhenius Plots from TPR of Fe2O3 (K-1 s-1) c b -15 -16 -17 -18 -19 a dry series main peak Ea = 111 kJ/mol wet series low T peak wet series main peak 12 13 14 15 16 17 18 Catalysis and Catalysts - TPR and TPS

19. (10-2 K-1) a 4 3 2 1 0 b c d e f 500 550 600 650 Temperature (K) Calculated Fe3O4 Fe TPR Peaks three-dimensional nucleation (Avrami Erofeev); f() = 3(1-) [-ln(1-)]2/3 two-dimensional phase boundary; f() = (1-)1/2 two-dimensional nucleation (Avrami Erofeev); f() = 2(1-) [-ln(1-)]1/2 three-dimensional phase boundary; f() = (1-)2/3 unimolecular decay; f() = (1-) Three-dimensional diffusion (Jander); f() = [3(1-)2/3]/[2(1-(1-)1/3)] Catalysis and Catalysts - TPR and TPS

20. a b 500 550 600 650 Temperature (K) Comparison of Measured and Calculated Fe3O4 Fe TPR Peaks three-dimensional nucleation (Avrami Erofeev); f() = 3(1-) [-ln(1-)]2/3 calculated Wet series Dry series Catalysis and Catalysts - TPR and TPS