The OH laser induced fluorescence method was used to study the kinetics of CHOO reacting with SO, (HO), CHI and I atoms. Decay of CHOO is not strictly first-order since its self-reaction is rapid. With this consideration, we derived the rate coefficient of CHOO + SO/(HO)/CHI/I taking into account the contribution of the CHOO self-reaction. For the CHOO + SO reaction, the rate coefficient is measured to be (3.88 ± 0.13) × 10 cm molecule s at 10 Torr, which agrees very well with a previously reported value obtained by directly monitoring CHOO using the UV absorption method with the CHOO self-reaction considered. We did not observe obvious evidence for SO catalysed CHOO isomerization or the intersystem crossing effect in this reaction. CHOO + (HO) is supposed to account for the major sink of CHOO in the atmosphere, but previous rate coefficient measurements were not in good agreement. We have revisited this reaction including the self-reaction of CHOO and obtained the rate coefficient to be (7.53 ± 0.38) × 10 cm molecule s at 60 Torr and 300 K. The rate coefficients of CHOO + CHI and CHOO + I were measured to be (5.2 ± 2.6) × 10 and (2.2 ± 1.1) × 10 cm molecule s respectively.

Supported noble metal nanoclusters and single-metal-site catalysts are inclined to aggregate into particles, driven by the high surface-to-volume ratio. Herein, we report a general method to atomically disperse noble metal nanoparticles. The activated carbon supported nanoparticles of Ru, Rh, Pd, Ag, Ir and Pt metals with loading up to 5 wt. % are completely dispersed by reacting with CH3I and CO mixture. The dispersive process of the Rh nanoparticle is investigated in depth as an example. The in-situ detected I• radicals and CO molecules are identified to promote the breakage of Rh-Rh bonds and the formation of mononuclear complexes. The isolated Rh mononuclear complexes are immobilized by the oxygen-containing functional groups based on the effective atomic number rule. The method also provides a general strategy for the development of single-metal-site catalysts for other applications.

The negative temperature dependence of the rate coefficient for CH2OO + NH3 reaction was observed using an OH laser-induced fluorescence method.

Hydrogen chloride (HCl) contributes substantially to the atmospheric Cl; both species could affect the composition of Earth’s atmosphere and the fate of pollutants. Here, we present the kinetics study for syn-CH3CHOO reaction with HCl using experimental measurement and theoretical calculations. The experiment was conducted in a flow tube reactor at a pressure of 10 Torr and temperatures ranging from 283 to 318 K by using the OH laser-induced fluorescence (LIF) method. Transition-state theory and quantum chemistry calculations with QCISD­(T) were used to calculate the rate coefficients. Weak negative temperature dependence was observed with a measured activation energy of −(2.98 ± 0.12) kcal mol–1 and a calculated zero-point-corrected barrier energy of −3.29 kcal mol–1. At 298 K, the rate coefficient was measured to be (4.77 ± 0.95) × 10–11 cm3 s–1, which was in reasonable agreement with 2.2 × 10–11 cm3 s–1 from the theoretical calculation.

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The kinetics of the simplest Criegee intermediate (CH2OO) reaction with tert-butylamine ((CH3)3CNH2) was studied under pseudo-first-order conditions with the OH laser-induced fluorescence (LIF) method at the temperature range of 283–318 K and the pressure range of 5–75 Torr. Our pressure-dependent measurement showed that at 5 Torrthe lowest pressure measured in the current experimentthis reaction was under the high-pressure limit condition. At 298 K, the reaction rate coefficient was measured to be (4.95 ± 0.64) × 10–12 cm3 molecule–1 s–1. The title reaction was observed to be negative temperature-dependent; the activation energy of (−2.82 ± 0.37) kcal mol–1 and the pre-exponential factor of (4.21 ± 0.55) × 10–14 cm3 molecule–1 s–1 were derived from the Arrhenius equation. The rate coefficient of the title reaction is slightly larger than (4.3 ± 0.5) × 10–12 cm3 molecule–1 s–1 of the CH2OO reaction with methylamine; the electron inductive effect and the steric hindrance effect might play a role in contributing to such difference.

Sulfur poisoning and regeneration are global challenges for metal catalysts even at the ppm level. The sulfur poisoning of single-metal-site catalysts and their regeneration is worthy of further study. Herein, sulfur poisoning and self-recovery are first presented on an industrialized single-Rh-site catalyst (Rh 1 /POPs). A decreased turnover frequency of Rh 1 /POPs from 4317 h À 1 to 318 h À 1 was observed in a 1000 ppm H 2 S cofeed for ethylene hydroformylation, but it self-recovered to 4527 h À 1 after withdrawal of H 2 S, whereas the rhodium nanoparticles demonstrated poor activity and self-recovery ability. H 2 S reduced the charge density of the single Rh atom and lowered its Gibbs free energy with the formation of inactive (SH)Rh(CO)(PPh 3frame) 2 , which could be regenerated to active HRh-(CO)(PPh 3 -frame) 2 after withdrawing H 2 S. The mechanism and the sulfur-related structure-activity relationship were highlighted. This work provides an understanding of heterogeneous ethylene hydroformylation and sulfur-poisoned regeneration in the science of single-atom catalysts.

Rationale:Thyroid-associated orbitopathy (TAO) is most often seen in patients with autoimmune thyroid disease. Data about TAO occurred in patients with thyroid carcinoma are rare. We give a report of 5 patients to present the clinical characteristics, treatment, and prognosis of this type of case.Patient concerns:Five thyroid carcinoma patients presented with orbitopathy. Among them, two patients (patient 1 and 4) were hyperthyroid and TSH receptor antibody (TRAb) positive, two patients (patient 3 and 5) were euthyroid and displayed slightly elevated TRAb titres, one patient (patient 2) was euthyroid and TRAb negative.Diagnoses:They were diagnosed as thyroid carcinoma and TAO.Interventions:Patient 1 underwent total thyroidectomy, intravenous glucocorticoids (GCs) therapy, orbital decompression surgery and oral GCs therapy. Patient 2 and 3 only received total thyroidectomy. Patient 4 received sub-total thyroidectomy and oral GCs therapy. patient 5 didn’t received thyroidectomy and underwent intravenous GCs therapy for 2 courses.Outcomes:Patient 1,2,3 showed an improvement of TAO at the final follow-up. Patient 4,5 showed no improvement of TAO at the final follow-up.Lessons:When TAO present in patients with thyroid nodules, the possibility of thyroid carcinoma should be considered, and the nature of these nodules should be carefully evaluated. In some patients with thyroid carcinoma and TAO, the remission of TAO can be seen post total thyroidectomy. But for other patients, besides thyroidectomy, an adequate dose and course of intravenous GCs treatment and even ocular surgery are also needed.