Method for preparing high-specific-surface-area chromium-based fluorination catalyst

The invention discloses a method for preparing a high-specific-surface-area chromium-based fluorination catalyst. The method comprises the process that a chromium-based fluorination catalyst precursor is prepared from raw materials including chromic nitrate and a chelating agent with a sol-gel auto-combustion method, the chelating agent is carboxylate containing carboxyl groups or aliphatic amines; besides, raw materials for preparing the chromium-based fluorination catalyst precursor further include a metal nitrate aid. According to the method, the catalyst precursor is prepared with the sol-gel auto-combustion method, the technology is simple, control is convenient, and repeatability is good; the adopted raw materials are easy to obtain, the price is low, the practicability is high, and the method has the broad application prospect.