Hydrogen Production. Daniel M. Ginosar April 9, ISU Physics Colloquium. gov.

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1 Catalysts Research for Nuclear Hydrogen Production gov Daniel M. Ginosar April 9, 2012 ISU Physics Colloquium

2 Ancient Chinese Proverb

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17 Greenhouse Gases and Global Warming

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19 Peak Oil

20 140 Imported Crude Oil Prices Based on $ in Real Price Dollars Per Barrel Short Term Energy Outlook-December 2009

21 Nat. Gas Biomass Coal, H 2 Direct Liquefaction Hydrogen C, H 2 Dimethyleither ith F-T liquids Mixed Alcohols

22 Environmentally sound H 2 is needed Current hydrogen production technology Methane steam reforming (significant CO 2 byproduct) Electrolysis (low efficiency, high cost) Advanced d hydrogen technology Primary energy source should: Have low carbon footprint, high efficiency, high operating temperature

23 Hydrogen production using water splitting cycles Water is split to produce hydrogen at moderate temperatures Thermal solar, or high temperature nuclear heat can drive reactions Energy security, no dependence on imported oil, no dependence on finite fossil fuels, no greenhouse gas emissions (CO2 )

24 Sulfur-Iodine (S-I) Thermochemical Cycle H 2 O O 2 H 2 SO 2 I C 1/2O 2 +SO 2 + H 2 O SO 2 +2H 2 O+I 2 I 2 + H 2 H 2 SO 4 H 2 SO 4 + 2HI 2HI H 2 SO 4 2HI Catalyst Required Sulfur Iodine Catalyst Required (1) H 2 SO 4 H 2 O + SO 2 + 1/2O 2 (2) 2HI I 2 + H 2 (3) (3) 2H 2 O + SO 2 + I 2 H 2 SO 4 + 2HI

25 HI Decomposition 2HI I 2 + H 2 Moderate temperature t catalytic ti reaction: o C Equilibrium limited Highly endothermic Prior Investigations (1970 s to 1980 s) Supported Pt or Pd (soluble in liquid phase) Activated Carbon Activated Carbons not identified No catalyst t stability studies No information on what makes highly active catalyst

26 HI Decomposition Test System Atmospheric pressure Gas phase reaction Aqueous HI (55 wt% HI typical) feed Samples of 100 to 200 mg, 40 to 60 mesh

27 Temperature Dependent Activity 14% Hydroge n Yield (mo l % ) 12% 10% 8% 6% 4% 2% AC from Coal San Juan AC 1 San Juan AC 2 San Juan AC 3 San Juan AC 4 San Juan AC 5 San Juan AC 6 Variety of activated carbons with SA ranging from 200 to 2,200 m 2 /g. Best activated carbon had moderate surface area of 1,100 m 2 /g. Low activity below 350 C 0% WHSV = 70 g HI/g cat/hr Temperature ( C)

28 Activated Carbon Characterization What properties are responsible for the wide range of activity? Ran variety of analysis to develop activity/property relationships Nitrogen physisorption yssopto Ash Content Boehm Titrations-acid and base sites Contact ph TPD experiments DRIFTS

29 Activated carbon properties Ash content: 0 86% Carbon fraction: (100 14%) BET surface area: Mesoporous (< 2 nm) SA %: 1 16% Total sites (meq / 100 g): 0 165

30 Catalytic Activity Correlation 12% d (mol%) ) )) Hydrog gen Yeild 10% 8% 6% 4% 2% 500 C 450 C 400 C 0% (Meso SA Fraction)*(Carbon Fraction)*(Total Acid Sites)

31 Activity / Property Relationships Hydrogen yield is greatest when: Surface area is moderate (mesoporous SA high) (500m 2 /g < BET < 1500 m 2 /g) Ash content t is low (< 10%) Total acid sites are high (> 50meq/100g) Commercial activated carbon samples requested with desired properties from Norit and Carbon Activated Inc. NHI Integrated Laboratory Scale Demonstration Project requires NHI Integrated Laboratory Scale Demonstration Project requires 12 Kg 200 L/hr H 2 production

32 Stability of Select Commercial ACs 8% n Yield (m mol %) Hydroge 7% 6% 5% 4% 3% 2% 1% Norit RX 1.5 Extra Darco MRX A.C. from Coconut AC A.C. CoalBase 0% Time (Hrs) Temperature 475 C, WHSV = 130 g HI/g cat/hr

33 Extended Stability of Norit RX 1.5 Extra 14% 650 H ydrogen Yield ( mol %) 12% 10% 8% 6% 4% 2% Rea actor Tem mperatu ure ( C) 0% WHSV = 6 g HI/g cat/hr Time on Stream (days)

34 Extended Stability of Commercial AC 0.09 n Rate yst ) n Production s/hr/g cataly Hydrogen (moles WHSV = 140 hr -1 CO = 30 ppm CO 2 = 110 ppm Fresh Activated Carbon Activated Carbon Recovered From 33 Day Study Longevity Study WHSV = 6 hr -1 WHSV = 140 hr -1 CO = 30 ppm CO 2 = 45 ppm Time on Stream (Days) Temp = 450 C

35 Sulfur-Iodine (S-I) Thermochemical Cycle H 2 O O 2 H 2 SO 2 I C 1/2O 2 +SO 2 + H 2 O SO 2 +2H 2 O+I 2 I 2 + H 2 H 2 SO 4 H 2 SO 4 + 2HI 2HI Catalyst Required H 2 SO 4 2HI Sulfur Iodine Catalyst Required (1) H 2 SO 4 H 2 O + SO 2 + 1/2O 2 (2) 2HI I 2 + H 2 (3) (3) 2H 2 O + SO 2 + I 2 H 2 SO 4 + 2HI

36 H 2 SO 4 Decomposition Reaction H 2 SO 4 SO 2 + H 2 O + ½O 2 H 2 SO 4 SO 3 + H 2 O Thermal SO 3 SO 2 + ½ O 2 Catalytic High temperature catalytic reaction: o C Equilibrium limited Highly endothermic Very harsh catalyst environment (high temp steam, O 2, SO 2, SO 3,H 2 SO 4, and HI, I 2 impurities) No catalysts known to withstand similar environment Goal: Identify or develop highly active, stable catalysts

37 SO 2 Yields Over 1 wt% Pt/TiO 2 100% SO2 Yield (mol %) 80% 60% 40% 20% Equilibrium Experimental 0% Temperature ( C) Concentrated sulfuric acid (96 wt%) at a WHSV = 3.3 g acid/g cat./hr.

38 1wt% Pt/TiO 2 longevity test 0.05 g 010g g What are the causes of deactivation?

39 Pt/TiO 2 Catalyst Deactivation BET surface area declined for Pt/TiO 2 Pt level stable for 24 hrs, declined 30% for 240 hrs on 0.1% Pt, 5% on 1% Pt over 548 hrs Significant growth in Pt particle size XPS analysis found significant changes in surface Pt Pt/TiO 2 : oxidized Pt (.1%) and metallic Pt found (1%) Deactivation may be due to loss of support surface area, Pt sintering, oxidation, and vaporization Petkovic, Ginosar, Rollins, Burch, Pinhero, Farrell, Applied Catalysis A General, 338 (2008)

40 Catalyst Exposed to High High-Temperature Temperature H2SO4 a c b d SEM images of 1wt% Pt on TiO2 after: a) 0 hours, b) 24 hours, c) 66 hours, and d) 548 hours at 820 C. Numbered labels correspond to EDS analysis points. Scale bars: 1.0 μm. Petkovic, Ginosar, Rollins, Burch, Pinhero, Farrell, Applied Catalysis A General, 338 (2008)

41 Melting Temperatures of Precious Metals ( C) Ruthenium (Ru) Rhodium (Rh) Palladium (Pd) Silver (Ag) Osmium (Os) Iridium (Ir) Platinum (Pt) Gold (Au)

42 Transient SO 2 Yields over PGM Catalysts 50% 45% SO O2 Yield (m mol %) 40% 35% 30% 25% 20% 15% Pt/TiO2 Pd/TiO2 Rh/TiO2 Ir/TiO2 Ru/TiO2 TiO2 10% 5% 0% Time on Stream (Hrs) 850 C and a WHSV of 240 hr-1

43 Deactivation and End of Run Reaction Rate at 72 hr Deactivat tion Rate (mol/g cat./hr 2 ) SO2 Prod duction Ra ate (mol /hr/g cat.) Pd Pt Rh Ir Ru 0.00 Pd Pt Rh Ir Ru Catalytic Metal Catalytic Metal 850 C and a WHSV of 240 hr -1

44 SO 3 Decomposition Rashkeev, Ginosar, Petkovic, Farrell, Catalysis Today, in press, 2008

45 a) c) 2 E(eV) Ru Ir b) 1 Rh Pt 0 Pd O + O O 2 Rashkeev, Ginosar, Petkovic, Farrell, Catalysis Today, in press, 2008

46 Bimetalic Catalysts HMP PGM Pt Oxide Support Pt / PGM Initial State Oxide Support Core/Shell Oxide Support Solid Solution

47 Activities of 1% Pt catalysts w/ PGMs ate (mol/hr r/g catal) SO O2 Prod. R wt% Pt 0.3% Ir - 1 wt% Pt 0.3% Rh - 1 wt% Pt 03wt%Ru 0.3-1wt%Pt Reaction Time (hrs) 850 C and a WHSV of approximately 2,000 g acid/hr/g catalyst.

48 Month Long Catalyst Testing 0.3 wt% Ru 1.0 wt% Pt/TiO 2 catalyst 120% 100% SO2 Yie eld (mol %) 80% 60% 40% 20% 0% Time (days)

49 End of Run Activity 7 SO O2 Prod Rate (mol/ /hr/g cata l) wt% Ru - 1.0wt% Pt/TiO wt% wt% Pt/TiO2 Pt/TiO2 Series Time (days) 1.0 wt% Pt/TiO 2 and the 0.3 wt% Ru 1.0 wt% Pt/TiO 2 catalyst. For times to 31 days, catalyst masses are 1.0 g. For times greater than 31 days, catalyst masses are 0.1 g.

50 Summary Thermochemical cycles produce harsh environments for catalytic materials. Pt is an effective catalyst for H 2 SO 4 decomposition, but does not posses needed long term stability. Initial trials mixing Pt with other PGMs have not yet generated active and stable materials. Some activated carbons maybe active and stable for HI decomposition. HI decomposition catalyst with better low temperature activity are highly desired.

51 Acknowledgements