Amine-containing adsorbents have been extensively investigated for post-combustion carbon dioxide capture due to their ability to chemisorb low-concentration carbon dioxide from a wet flue gas. However, earlier studies have focused primarily on the carbon dioxide uptake of adsorbents, and have not demonstrated effective adsorbent regeneration and long-term stability under such conditions. Here, we report the versatile and scalable synthesis of a functionalized-polyethyleneimine (PEI)/silica adsorbent which simultaneously exhibits a large working capacity (2.2 mmol g−1) and long-term stability in a practical temperature swing adsorption process (regeneration under 100% carbon dioxide at 120 °C), enabling the separation of concentrated carbon dioxide. We demonstrate that the functionalization of PEI with 1,2-epoxybutane reduces the heat of adsorption and facilitates carbon dioxide desorption (>99%) during regeneration compared with unmodified PEI (76%). Moreover, the functionalization significantly improves long-term adsorbent stability over repeated temperature swing adsorption cycles due to the suppression of urea formation and oxidative amine degradation.

Chiral imidazolium salts bearing sulfide and phosphine have been synthesized from chiral ferrocenylamine, and their rhodium and iridium complexes have been characterized by an X-ray diffraction study.

Sterically demanding and conformationally stable N,N'-ditertiaryalkyl-N,N'-diphenyl acyclic diaminocarbenes (ADCs) were developed. Bulky ADC-Au catalysts not only showed competitive reactivities in hydroamination and enyne cyclization but also demonstrated unique ligand properties different from bulky N-heterocyclic carbene (NHC) counterparts.

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This paper reports the experimental demonstration of the novel swing adsorption reactor cluster (SARC) concept in a multistage fluidized bed reactor with inbuilt heat-transfer surfaces for postcombustion CO2 capture at a capacity up to 24 kg-CO2/day. SARC employs combined temperature and vacuum swings (VTSA), driven by heat and vacuum pumps, to regenerate the solid sorbent after CO2 capture. The laboratory-scale reactor utilized a vacuum pump and a heating oil loop (emulating the heat pump) to demonstrate 90% CO2 capture from an N2/CO2 mixture approximating a coal power plant flue gas fed at 200 NL/min. In addition, dedicated experiments demonstrated three important features required for the success of the SARC concept: (1) the polyethyleneimine sorbent employed imposes no kinetic limitations in CO2 adsorption (referred to as carbonation) and only minor nonidealities in regeneration, (2) a high heat-transfer coefficient in the range of 307–489 W/m2 K is achieved on the heat transfer surfaces inside the reactor, and (3) perforated plate separators inserted along the height of the reactor can achieve the plug-flow characteristics required for high CO2 capture efficiency. Finally, sensitivity analysis revealed the expected improvements in CO2 capture efficiency with increased pressure and temperature swings and shorter carbonation times, demonstrating predictable behavior of the SARC reactor. This study provides a sound basis for further scale-up of the SARC concept.

Chiral ferrocenyl imidazolium salts were obtained from optically pure ferrocenyl alcohols or acetates by substitution with retention of configurations. Their rhodium and iridium complexes were synthesized and applied to asymmetric hydrogenations. The benzimidazolylidene-iridium complex showed up to 52.6% ee in the transfer hydrogenation of 4′-methylacetophenone. Scheme 4. Substitution of the Chiral Ferrocenyl Acetates Scheme 5. Substitution with Benzimidazole Scheme 6. Synthesis of Rh(I)-and Ir(I)-Carbene Complexes

Sodium nitrate (NaNO 3 ) and other alkali nitrates are known to accelerate the CO 2 11 absorption rate of MgO above their melting points. This absorption rate is further enhanced if 12 absorption is done after partial desorption. Moreover it does not show any induction period 13 which is otherwise present if absorption is done after complete desorption. A thorough study of 14 various factors affecting the rate after partial desorption is done in this work. We exposed a 15 sample to CO 2 for several different periods before partial desorption and exposed to N 2 for 16 several different periods during partial desorption in a thermogravimetric analyzer. Absorbents 17 were also characterized by XRD, BET and SEM and studied in in-situ IR cell to understand the 18

Self-assembled monolayers (SAMs) of 1,1′-disubstituted ferrocene derivatives, i.e., 1,1′-bis(11-mercaptoundecyl)ferrocene (1) and 1-decyl-1′-(11-mercaptoundecyl)ferrocene (2), on a gold surface were prepared, and their structural and electrochemical properties were characterized by reflection-absorption infrared spectroscopy (RAIRS), ellipsometry, cyclic voltammetry (CV), and subtractively normalized interfacial Fourier transform infrared spectroscopy (SNIFTIRS). From the RAIR spectral features, both molecules, 1 and 2, were found to chemisorb on gold as thiolates after deprotonation. The peak positions of the methylene stretching modes indicated that the alkyl chains of 1 and 2 assume disordered structures on the gold surface. The thicknesses of the monolayers 1 and 2 on gold were determined by ellipsometry to be 2.27 ( 0.10 and 2.30 ( 0.10 nm, respectively. In the CV experiments, symmetric redox peaks were identified at ca. 0.32 and 0.30 V versus saturated calomel electrode (SCE) for the SAMs of 1 and 2, respectively. The surface coverage values determined from the CV of 1 and 2 were 3.4 × 10 -10 and 3.2 × 10 -10 mol/cm 2 , respectively. Both SAMs at full-coverage limits were stable in neutral (0.2 M NaClO4) as well as in acidic (0.2 M HClO4) medium, suggesting that hardly any decomposition of the ferricinium cation occurred for the SAMs prepared from disubstituted ferrocene derivatives. In particular, the SAMs of 1 were stable irrespective of the surface coverage, displaying the bonding capability of dithiols to gold; the submonolayer of 2 was slightly unstable in neutral medium. The SNIFTIR spectral data suggested that the alkyl chain of the two SAMs takes a more upright orientation when the ferrocene moiety is oxidized to a ferricinium cation.