Study on the Performance of the Zr-Modified Cu-SSZ-13 Catalyst for Low-Temperature NH3-SCR.

Cu-SSZ-13 and Zr-modified Cu-SSZ-13 catalysts with different Zr/Cu mass ratios were prepared by ion-exchange and impregnation methods, respectively. The NH3-SCR performance tests were performed using the catalyst performance evaluation device to investigate the effects of different Zr/Cu mass ratios on the catalyst ammonia-selective catalytic reduction (NH3-SCR) performance. X-ray diffraction, ICP-OES, BET, NH3 temperature-programed desorption (NH3-TPD), H2 temperature-programmed reduction (H2-TPR), X-ray photoelectron spectrometry, and in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS) were used to characterize the catalysts. The results show that the prepared Cu-SSZ-13 catalyst had good catalytic activity. Zr introduction was carried out on this basis. The results showed that proper Zr doping improved the catalytic activity at low temperatures and widened the high-temperature stage, with an optimal activity stage at a Zr/Cu mass ratio of 0.2. The NO x conversion efficiency was close to 100% at 200 °C and over 80% at 450 °C. The active species were well dispersed on the catalyst surface, and the metal modification did not change the crystal structure of the zeolite. The NH3-TPD results showed that the Zr-modified catalyst had more abundant acid sites, and the H2-TPR results indicated that the Cu species on the catalyst had excellent reducibility at low temperatures. The interaction between Cu and Zr could regulate the Cu+ and Cu2+ proportion on the catalyst surface, which facilitated the increase in the Cu+ for fast SCR reaction at low temperatures. With abundant acid sites and both SCR reactions following the Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) mechanism on the catalyst surface at a low temperature of 150 °C, more abundant acid sites and reaction paths created favorable conditions for NH3-SCR reactions at low temperatures.

Experimental Research on Distribution Characteristics of NO x Conversion Efficiency of a Diesel Engine SCR Catalyst.

An experimental investigation of the distribution characteristics of NO x conversion efficiency inside a selective catalytic reduction system is presented in this paper. Wash-coated and extruded vanadium-based selective catalytic reduction catalysts were investigated under an ANR (ammonia nitrogen ratio) of 1.0 and various exhaust gas temperature and flow rate conditions. A moveable sampling probe was located at various measuring points on the exit cross section of the selective catalytic reduction catalyst shell, and the final distribution maps of NO x conversion efficiency were obtained by the interpolation of measured data. The experimental result showed that the distribution of NO x conversion efficiency of the wash-coated selective catalytic reduction catalyst at the exit cross section was extremely nonuniform and the efficiency of the extruded SCR catalyst was uniform with a higher distribution at the center. A comparison experiment with 180° rotation of the selective catalytic reduction catalysts was implemented, and the efficiency distribution map of the wash-coated selective catalytic reduction catalyst also rotated 180° but that of the extruded selective catalytic reduction catalyst remained unchanged. The uniformity coefficient of the extruded selective catalytic reduction catalyst was higher than that of the wash-coated selective catalytic reduction catalyst used in this study.

The correlation between intimate relationship, self-disclosure, and adaptability among colorectal cancer enterostomy patients.

ABSTRACT: The postoperative physiological changes and psychological pressure of cancer patients affect the patient's adaptability to the disease, and thus affect the spousal intimate relationship. This study aimed to evaluate the correlation between spousal intimate relationship, self-disclosure, and adaptability among colorectal cancer (CCI) patients with enteric stoma.This cross-sectional study selected patients with CCI in Henan Province from February 2018 to October 2020. The Marital Adjustment Test (MAT), the Distress Disclosure Index scale, and the Ostomy adjustment inventory-20 scale were used to collect relevant data of the participants. A Pearson correlation analysis was used to test the correlation between variables, and multiple stepwise regression analysis was used to test the influence of general information on the intimate relationship, self-disclosure, and adaptability.Among the respondents, 42.6% had a spousal intimate relationship problem, 58.4% had a low or moderate level of self-disclosure, and 90.8% were at a low or moderate level of adaptation. Education background, self-care ability, and postoperative time were associated with a couple's intimate relationship. Average monthly household income, gender, and place of residence were associated with self-disclosure. Self-care ability, average monthly household income, postoperative time, and educational background were associated with adaptation.Healthcare workers should provide more health education training to guide CCI enterostomy patients to express their thoughts and feelings with each other increase self-disclosure, so as to enhance their intimate relationship then improve their adoption to ostomy, finally elevate their quality of life.