ABSTRACT
To address climate change, the energy crisis, and global warming, hydrogen (H2) can be used as a potential energy carrier because it is clean, non-toxic and efficient. Today, the mainstream industrial method of H2 generation is steam reforming of methanol (SRM). In this process, a zinc-based commercial catalyst is usually used. In this work, a ZnO-ZnCr2O4 catalyst was successfully synthesised by the glycine nitrate process (GNP) and developed for use in H2 production by SRM. The specific surface area, porous structure and reaction sites of the zinc-based catalyst were effectively increased by the preparation method. The as-combusted ZnO-ZnCr2O4 composite catalyst had a highly porous structure due to the gas released during the GNP reaction process. Moreover, according to the ZnO distribution and different G/N ratios, the specific surface area (S BET) of the as-combusted ZnO-ZnCr2O4 catalyst varied from 29 m2 g-1 to 46 m2 g-1. The ZnO-ZnCr2O4 composite catalyst (G/N 1.7) exhibited the highest hydrogen production, 4814 ml STP min-1 g-cat-1, at a reaction temperature of 450 °C without activation treatment. After activation, the ZnO-ZnCr2O4 composite catalyst achieved hydrogen production of 6299 ml STP min-1 g-cat-1 at a reaction temperature of 500 °C. The hydrogen production performance of the ZnO-ZnCr2O4 composite powder was improved by the uniform addition of ZnO to ZnCr2O4. Based on the performance, this ZnO-ZnCr2O4 composite catalyst has great potential to have industrial and economic impact due to its high efficiency in hydrogen production.
ABSTRACT
INTRODUCTION: Anti-interferon-gamma (anti-IFN-γ) autoantibody increases susceptibility to lower-virulence pathogens and causes immunodeficiency syndrome in HIV-negative patients. PATIENT CONCERNS: A 69-year-old Chinese man presented with a 2-month history of pruritic skin lesions on his forearms, trunk, and legs. He was diagnosed with 5 opportunistic infections without conventional immunosuppression-associated factors in past. The most conspicuous characteristics were recurrent pulmonary infection, persistent immunoglobulin E elevation and eosinophilia during the whole disease course. DIAGNOSIS: Enzyme-linked immunosorbent assay showed anti-IFN-γ autoantibody positive. The final diagnosis for the patient was adult-onset immunodeficiency due to anti-IFN-γ autoantibody, non-tuberculous mycobacterial (NTM) infection and reactive dermatosis. INTERVENTIONS: The patient underwent long-term anti-NTM and corticosteroid maintenance treatment. OUTCOMES: The patient was followed for 2 years during which opportunistic infection no longer happened, the immunoglobulin E level and eosinophil count reduced, the autoantibody levels remained largely steady and lung lesions absorbed. CONCLUSION: Clinicians should be vigilant for NTM infection in patients with anti-IFN-γ autoantibodies, even when culture results are negative. Long-term anti-non-tuberculous mycobacteria and glucocorticoid regimens were effective.
