Designing a highly active doped‐carbon‐based oxygen reduction reaction (ORR) electrocatalyst with optimal stability is a must if large‐scale implementations of fuel cells are to be realized. Developing controllable doping strategies is essential for achieving highly active catalysts. Herein, a facile doping strategy is developed by designing a precursor material with unique core–shell nanostructure, whereby the Materials Institute Lavoisier (MIL) metal–organic framework (MOF) and polyaniline are core and shell components, and serving as oxygen and nitrogen precursors, respectively. A novel hollow loofah‐like carbon tube (HLCT) catalyst is derived from precursor material with controllable heteroatom‐doping concentrations through modulating the mass ratio of MOF/aniline. The optimal HLCT‐1/2 catalyst, with a MOF/aniline mass ratio of 1/2, exhibits excellent ORR activity and stability in an alkaline medium. Remarkably, the half‐wave potential (0.88 V) and the current density (4.35 mA cm−2) at 0.85 V of HLCT‐1/2 catalyst surpass that of commercial Pt/C. Such superior catalytic properties can be attributed to the high specific surface area and abundant active sites of loofah‐shape carbon tubes. Moreover, the O dopant modulates the content and distribution of N species, leading to the enhanced adsorption strength of oxygen molecules on catalyst surface, promoting the activation of oxygen, and thus achieving higher electrocatalytic activity.

The simultaneous removal of dust, NOx, and SO2 in flue gas is a hot topic in the field of air pollution control. This work established a simultaneous removal system that could remove dust, NOx, HCl, and SO2 in a single step, which can be operated under a wide range of test conditions. Brunauer–Emmett–Teller analysis, X-ray photoelectron spectroscopy, thermogravimetric analysis, scanning electron microscopy, and X-ray fluorescence technique were used to determine the pore structure and surface chemistry of the ceramic catalytic filter tube. The results indicated that SO2 and HCl could be removed using sodium bicarbonate (NaHCO3) or calcium hydroxide [Ca­(OH)2] as the sorbent, whereas NOx is catalytically converted with NH3 and O2 to N2 and H2O. The denitrification efficiency is above 95% in the reaction temperature range of 260–350 °C. The removal efficiency of SO2 and HCl at a Ca/S molar ratio of 2.0 can reach up to 85 and 91%, respectively. Ca­(OH)2 showed lower removal efficiency of SO2 and HCl compared with NaHCO3 as the sorbent. Injection of sorbents upstream of the ceramic catalytic filter tube can prevent potential poisoning to the catalyst by particulates or acid gas. Moreover, the ceramic catalytic filter tube consists of a fine-particulate filter membrane as the surface layer, V2O5 and WO3 as the medium layer, and alumosilicate fibers as the final support layer. The NH3–NOx reaction was conducted under dust-free and SOx-free atmospheres and without diffusion restriction, and thus has almost 100% utilization of the catalyst’s intrinsic activity.