The further commercialization of renewable energy conversion and storage technologies requires heterogeneous electrocatalysts that meet the exacting durability target. Studies of the stability and degradation mechanisms of electrocatalysts are expected to provide important breakthroughs in stability issues. Accessible in situ/operando techniques performed under realistic reaction conditions are therefore urgently needed to reveal the nature of active center structures and establish links between the structural motifs in a catalyst and its stability properties. This review highlights recent research advances regarding in situ/operando techniques and improves the understanding of the stabilities of advanced heterogeneous electrocatalysts used in a diverse range of electrochemical reactions; it also proposes some degradation mechanisms. The review concludes by offering suggestions for future research.

Water-based drilling fluids (WBDFs) that are susceptible to high temperature and saline pollution always exhibit poor ability to control fluid loss and seriously threaten the operation security of oil well drilling; especially, ultradeep well WBDFs that can simultaneously tolerate high salinity and temperature of over 200 °C are difficult to obtain. Herein, a zwitterionic silica-based hybrid nanomaterial (ZSHNM) with a spherical morphology (50−150 nm) was synthesized, and its filtration performance was thoroughly investigated. ZSHNM showed an extraordinary long-term (≥10 months) dispersion stability even at high concentrations in water and possessed remarkable tolerance to high temperature and salinity. Typically, merely adding 2 wt % ZSHNM in WBDFs could achieve an excellent filtration performance even at 240 °C, and with 11 wt % CaCl 2 or 36 wt % NaCl added, it showed the best performance to our knowledge. The results suggested that the sodium bentonite (Na-Bent) dispersion could be well stabilized in the presence of ZSHNM even at high temperature and with the presence of cations. Additionally, the silicate core could improve the thermal stability of ZSHNM, whereas the zwitterionic shell could form complexes with cations and further mitigate the aggregation of Na-Bent particles. Thus, the particle size distribution in WBDFs could be finely regulated similar to that in neat Na-Bent dispersion. Furthermore, given the zwitterionic ZSHNM filled in the micro−nanopores among the Na-Bent particles, a compact and lowpermeability filter cake was readily formed and ultimately reduced the drilling fluid loss during the filtration process. This work provided a versatile strategy to address the high temperature and high salinity tolerance of WBDFs synchronously, thereby pioneering a new way to develop high-performance drilling additives for ultradeep and complex wells.